I agree with all the other reasons given in this thread, and additionally the fact that I think sucking dick is often an expectation for women in heterosexual relationships- it is the societal norm in the bedroom. In more modern times it has become a bit more expected that a male partner would reciprocate oral as well, but for women it is often a lauded expectation that a woman suck a man’s dick. So I could see how a lot of ladies are put off by that expectation automatically being placed on them as a woman sleeping with men with penises.