I'm not talking about what people would like to see, I'm talking about how lesbians are portrayed in mainstream media and how frequently they appear. My point is that there are not a lot of lesbian or bisexual women in mainstream media (characters) who were not put there to entertain male viewers.
Gay male characters on TV are a bit more common, though I think they do tend to suffer a lot of stereotyping.
I'm sure there is a lot of interest in seeing sexual diversity (and all forms of diversity) in mainstream media, but those with the power to make it don't often seem to realize that.