"All they talk about is how good their sex is"
The same can be said of male rappers, but I guess guys would rather listen to other guys talk about how much sex they get, but when a chick talks about it it's a problem.
There are very few rappers male or female that actually spit some real life ****, not just a bunch of pimpin' nonsense.
"their rhyme schemes, voices, delivery, punchlines, metaphors, lyircs."
You seem to be judging females in the same category and criteria as males...there are clearly chicks that have skills but since their voices aren't deep, and mad angry sounding so they get dissed. Most male rappers use male bravado in their lyrics to express how much of a P.I.M.P., or killer they are, which is really not something to aspire to IMO.
I see rapping like poetry, if you kick something from the heart, it doesn't matter who else likes it.
Now if ur talking about record sales, as a female mc ur basically screwed, if u go the "i'm sexy look at me, Lil Kim route" the chicks will hate, except the ones who are actually like that and the guys will hollar for a minute but don't expect any long term $. If u attempt to be like the guys, deep voice, thug, you'll get dissed for not being real. Basically to make it as a female mc you basically have to sound like a dope male mc.