I think men struggle with this form of feminism because it presents itself as an elitist club that men are exclusively prohibited from joining. Women have struggled with the reverse being true since time immemorial. As most people are conscious of this fact, the switch can feel something like petty revenge.
While women have more freedom now than ever (which is patently true) that doesn’t mean that institutionalized bias has been eradicated. In fact, perhaps due to natural pushback, those biases become reinforced somewhat.