Literally what they hate is that men found a hack to make them instantly high value, because having low value men to shit on gives them a way to appear higher worth themselves. They need men to reject so they can flex about their options to their other girlbosses. And then once these men have a hot, skinny foreign babe around their arm, a 'backwards' one that doesn't reflect their values, they instantly become high value, so there's this odd sense of missing out. They HATE that these men are going overseas and getting women hotter than them, while they can't get their Chad to stick around. They cannot handle that shit, dude
Of course they cannot, it's a method of escaping a non-beneficial arrangement for many men, and it instantly reduces women's negotiating power. Less desperate men = Less options for women all around. Women and women-worshiping men HATE perhaps more than anything women who lean into and satisfy traditional male wants in a woman (things like chastity, loyalty, submission, being kind), this is a good part of the reason for hating passport bros and most of the reason for hating the so called "pick-me" .
Almost every time I've seen a "pick-me" mentioned, it's a woman espousing or behaving in a traditional womanly way in relation to men, even in conservative circles! Whether you think them honest or not surely you want people to propagate this opinion if you're a person of traditional values, if people are adopting your views for social cred that's a sign of winning.
But no, they hate it. And it's because it destroys the pressure chamber, men love women, men want to have wives and kids, on some level they need to have them it's not optional. Which means if you can form a significantly sized chunk of women(most women) and they all agree to behave a certain way you can get a catch-22 where men are just kind of forced to accept that as the new standard. Women still get to have husbands and kids, but they now don't have to hold themselves to the same standards as before, enjoy new luxuries, more hedonistic pursuits, more obedient husbands ect. Defectors, scabs if you want to be humorous are hated because they are poking holes in that and once a certain threshold is reached the dam can no longer hold, individual women upping their attractiveness by being traditional is going to beat the appeal of a community of women lowering all of their attractiveness together and you're gonna have to go along if you want to keep up.
It's interesting in general how women publicly (mostly unmarried or unhappily married, "unowned" women effectively) have this sense of community or common investments that men are lacking, though on a smaller scale their friendships are less tight and loyal than men's.
That being said I do not wish for some odd HAPA evolutionarily escape and hope white men collectively can come to their senses, transform society, restrain women's agency and in doing so make everyone happier.