It's complicated. I can think of many reasons.
1. Some females have posted and been insulted by some SS members. Then they stopped posting. I tell female posters to have a thick skin lol. Of course, plenty of SS members are respectful and don't mind a friendly debate.
2. I don't think that many females are interested in this site. Or they quickly lose interest because it might SEEM like a bunch of misogynists.
3. They don't want to get swamped with PMs from guys hitting on them or asking 1000 questions lol.
4. With a few exceptions, I don't think females are interested in helping guys with this area of life. It's not necessarily some "We can't give our girly secrets out to men, the enemy" kind of conspiracy. It's more that most females have a binary or black and white view of men. You are either the attractive smooth "natural" or you are a loser, creeper. There is NO in between, and trying to "improve your game" or "make yourself more attractive" is looked at with scorn by most women. First, you were only an ugly loser. Now, in their eyes, you are a desperate TRYHARD loser who won't accept his lot in life, which is considered worse. F283000 said it best, "Women want James Bond. They just don't want you to become James Bond."
Notwithstanding, can some women give good honest advice? Yes, but it's not easy to find, and a guy needs some experience to tell the good advice from
the bad.