As someone living promiscuously, I'd say it's a correlation.

Some factors that lead people to a promiscuous livestyle also lead them to high risk behaviours, probably because they see promiscuous sexual behaviour also as risky and, in turn, desirable.

I met many that would frown upon condoms, but I also met many that would see them as no big deal.

I for one would count myself as risk averse, and got to that lifestyle through other motivations, and in turn, always ensured to stay safe.