Regarding how active a person's sex life is, I respect the individual's choice - whether that constitutes promiscuity or celibacy or something in between. They are all valid choices.
I just regret the fact that so many people make the decision based on either the perceived morality or the availability of sex, rather than what they actually desire.
I accept that it's unrealistic to expect this, but in a perfect world, everyone would have access to the sex they wanted, and shame wouldn't keep them from having it (or not having it, if that's their desire).