There are two ways of looking at public nudity - or generally being naked in front of anyone who's not specifically a nudist or an intimate partner, even if it happens to occur in private. People who are concerned about this behavior probably imagine the sort of person (probably not unlike themselves) who would not appreciate seeing a stranger naked - either because the stranger is not considered attractive and/or nudity offends the viewer on principle of modesty and/or they feel threatened by the encounter.
But when I think about being exposed in public and/or to strangers or non-nudist/non-intimate acquaintances, I see it differently. I imagine how delighted I would be to be on the other end and see the same thing. So, you see, exhibitionism isn't selfish. The same way that I started modeling in order to give back to the world what I appreciate in others - that is, sharing the sight of their naked bodies with the world - is how I view dressing in skimpy clothes, and how I imagine public nudity, if I had the guts and the assurance of not being charged as a criminal to do it.
Think of it like this - a sexy woman undressing in front of a window. (Obviously, this only works if you're attracted to women, but feel free to imagine a man or other circumstances altogether - I'm not judging). Who hasn't peered out of their window and wished they could see a sexy woman (or equivalent) undressing in front of a window across the block? I would love to see that. And I want to see more of it in the world. And how better to promote that outcome than to undress in front of windows myself? I follow Ghandi's advice: "be the change you wish to see in the world."
So obviously, there's a difference of perspective here - contrasted with the point of view that considers undressing in front of windows to be either distasteful (they just don't personally like it) or also immoral (there's something wrong with it). The point I would emphasize is that exhibitionists aren't actively trying to bother people - because they get some kind of sick thrill out of doing so. They just see the world differently, and are trying to spread what they perceive as joy, although others may see it otherwise.
But they're not alone in seeing things the way they see it. And besides, who gets to decide which of these opposing views takes precedence? If a woman on my street likes to undress in front of her window, why does my neighbor's disgust trump my delight, when it comes to deciding whether or not the woman should be permitted to proceed? We have a habit, in this so-called "democracy" of ours, to cater to complainers. The pursuit of happiness isn't so important to us as the avoidance of discomfort - cultivating a watered down public commons in which nobody has to feel offended. The reason I DON'T engage in a whole lot of public exposure (except in specific circumstances where I think there is an acceptably low level of being caught) is out of respect for the feelings of others.* But how often do those others respect MY feelings? This isn't an equivalent exchange, here.
*An argument could be made that I refrain from public exposure NOT out of concern for the feelings of others, but out of sheer self-interest. The fact is, I do care about others' feelings, if only because making other people feel bad makes me feel bad. I don't think this is uncommon; it's how we function as a social species. We tend to vilify selfishness and exalt selflessness to an unnatural extent, that promotes shame in the less-than-perfect (that is, all of us) at least as much as it promotes some of us to better behavior. The truth is, most people are selfless mainly for selfish reasons. And that's just fine. It's only the sociopaths that don't have that empathic connection with others that prevents them from doing harm to others, because doing so doesn't affect them the way it does the rest of us. In any case, my self-interest puts me at no lower a level than the self-interest of those who want to compel others to cover up simply because it makes them feel uncomfortable. I sacrifice to make others comfortable. They want others to sacrifice to make themselves comfortable. See the difference?
In the interest of fairness, we can imagine an alternate scenario in which the person undressing in front of the window is NOT someone I am attracted to. I think most people default to, "people I think are hot, I want to see naked. But if I don't think they're hot, they should cover up."** Obviously, this doesn't work when we take into account more than one person's tastes. So, again, we default to telling everybody to cover up, because taking away the joy of the people who would enjoy it is viewed as better than forcing the people who don't enjoy it to suffer.
**There are obviously other nuances to complicate the situation, such as people who only want to see hot people naked in limited circumstances, perhaps because they are uncomfortable embracing sexual thoughts outside of a private context, or people who have religious or some other kind of beliefs that prevent them from enjoying their sexual feelings at all. I think this is unfortunate, and one of the things I love most about the nudist worldview is this idea that, even if nudists don't typically view it from a sexual perspective, the exposure of people's bodies is not this private, intimate thing, but something that can be shared casually with strangers without all the baggage we normally load onto intimate encounters (including any kind of expectation of sexual activity), and devoid of the view that doing so is somehow immoral or represents a negative character flaw. Grappling with the beliefs of those who object to the nudists' casual approach to nudity is one of its most challenging obstacles to mainstream acceptance, and I don't have a solution to that problem. But I will say that I would be much happier living in a nudist-positive world than the one we currently live in, where people's bodies are shamed (whether they're attractive or not) and the sharing of visual beauty (entirely separate from any kind of sexual contact) is stigmatized to a life-defeating (in some cases literally, as we've occasionally seen with the more tragic teen sexting cases) extent.
Maybe it's not so bad from that perspective - prioritizing the avoidance of suffering over the elimination of pleasure - like letting a criminal go free rather than risking false imprisonment. But here's my argument. If you're not attracted to the person undressing in front of the window, you can just look away. Enter the nudist mindset. Most nudists I meet are not people I want or particularly enjoy seeing naked. Simply because I have particular tastes, and the percentage of the population that I view as attractive is a minority (and particularly smaller in a nudist context, where the demographic skews older and maler). But, as a nudist, seeing somebody that I don't find attractive naked doesn't bother me. And I've always maintained that looking at 99 people I find unattractive naked in order to get the privilege of seeing 1 person I do find attractive naked, that I would normally not get the chance to see naked, is more than worth it to me.
So here's the thing. Nudists posit a culture where naked bodies are not shocking, or offensive. Which is an idea that I love. To people with a limited understanding of it (which is most people, especially nudists), this should eliminate exhibitionism, which allegedly relies on shock value. Except that it doesn't, really. Taking the shock away would only improve exhibitionism, by removing a considerable obstacle to its enjoyment. Making nudity inoffensive means exhibitionists could expose themselves regularly without fanfare - getting enjoyment from the exposure without bothering anyone. EXACTLY like how exhibitionists currently get enjoyment out of strutting at the pool in string bikinis (I use this example to emphasize the gender disparity - that women are expected to show off, and that this is considered as unthreatening as milquetoast, while men who do it are quickly viewed with criminal suspicion), without offending anyone, and without this behavior involving any kind of mustache-twirlingly stereotypical depictions of sexual perversion, like masturbating on the waterslide in full view of children, or what have you (any time you mention exhibitionism to nudists, I swear, they think you're talking about public intercourse, and not just, you know, experiencing endorphins from the simple act of being seen and admired). I maintain that exhibitionism isn't a fringe fetish, but a common part of the human condition. Some of us just embrace it more fully than others.
In any case, exhibitionists and public nudity supporters (whatever their motivations might be, sexual or otherwise) should be viewed in light of their perspective on exposure being unremarkable, and not taken solely in light of current attitudes that view naked bodies akin to a deadly weapon. When somebody fantasizes about answering the door naked, they are not, largely, stroking themselves (whether literally or just figuratively) to thoughts of traumatizing strangers and forcing them to look at something that disturbs or disgusts them. No, if they are anything like me, they are imagining themselves AS THE VOYEUR, opening the door on somebody attractive, and how world-shatteringly delightful that experience would be (and how badly they wish it would happen - and that though they can't force a random attractive stranger to flash them, they CAN be the flasher in somebody else's fantasy). If some people lack the social capacity to recognize that this possibility may be rare, and that the cost of losing this particular lottery and ending up exposing oneself to somebody who does NOT appreciate it could be significant (and therefore going through with it and not keeping it in the realm of fantasy), then that is very unfortunate - and it paints an unfair portrait of exhibitionism. But it should not be mistaken for one of the foundational mechanisms of what drives the phenomenon of exhibitionism - or in the case of the nudist who simply wants more opportunities to remain undressed, without being accused of necessarily being an exhibitionist.