Why? Have you seen anyone saying that the brothels etc. were the best parts of the old games, or someone being pissed off because PoE won't feature sheep sex and porn shoots?
Because i somehow missed the threads dedicated to them, unlike romance which seem all over the place.
If they made a big deal about how they wouldn't allow the player character to buy the services of prostitutes because it's a dumb feature, then yes, a lot of people would write a lot of angry words about "censorship" and women invading the boys' club/mancave. Some have already done that in regards to female armor.
Anyway, as far as I remember, Torment (and one bizarre case in Heart of Winter) was the only IE game that allowed it. BG2 (and also BG I guess) had prostitutes, but you could only talk to them.