Point blank, political leanings nowadays often come down to basic human rights. Human rights are about the farthest possible thing from superficial. Hope this helps explain why women are so sensitive about it.

Also, regarding paying for stuff on dates: as a woman, I'm uncomfortable sometimes if a man pays, but it's not at all because I find it offensive. It's because, before I get to know him, I'm not sure about his intentions. Some men expect that paying for a date means they are entitled to sex. So I get a little nervous that he might then expect/demand sex in exchange.

In other words, if a woman is turned off, it usually comes down to fear. We're afraid. And the more men we encounter who aren't sensitive to that, and who complain about the fact that women's (statistically justified) fear makes us less receptive to their sexual desires for us, the more it makes us worry that the next guy will feel entitled to sex simply because he shelled out for a coffee, or that he might struggle to respect our boundaries and basic human rights.

Hoping this perspective helps shed light for men who feel mystified. ;)