|
Quite simply, blood. No matter how natural the monthly cycle is, blood is just not very acceptable, at least not as "front of the site" content. Some of the VOD sites has a bit of it, but they certainly don't advertise it and don't usually class it in a way that it is easy to find.
It also comes down to the same reason why scat isn't permitted either. While it is natural (nothing is more natural than shit, we all do it, even models!), it is just not acceptable.
From a totally personal standpoint, I also think that from a purely business standpoint, it comes down to what is sexy and what isn't. farting, shitting, peeing, and menstruation are all natural things, but I don't find them the least bit sexy and I suspect that 95% of the general population don't get off on them either. So I have never seen a valid business reason to fight the powers that be to get those things accepted, because that is a ton of work to address a very small and narrow market.
|