lol, this is very true. most woman also don't know how to turn on a man. they think the simple fact that they are present must make you want to sleep with them. and when they try to seduce you it's often horribly awkward.
i think a lot of it has to do with the fact that society hardwired certain gender roles into their brain. even most feminists have never critically reflected on how male gender roles influence their perception of men. men are supposed to be always horny and responsible for everything that has to do with sex: they are the ones who are supposed to want it, they have to initiate it, and they are the ones who have to perform. the woman is supposed to be passive in all these situations. if you don't initiate sex, a woman will feel that she must be horribly ugly, because if she wasn't you would want to sleep with her. the only other possibility that will cross her mind is that you are gay.
on top of that, a lot of them don't even know what they can do with their p*ssy. i had this weird conversation with an ex once, who said she wouldn't mind if i got a blowjob by another girl, because she knew how good her bj skills were and that other woman couldn't compete. but me sleeping with another woman would bother her, because the other girl might have a p*ssy that was build better than hers, and there was nothing she could do about it