Why are the labels "feminism" and "feminist" so necessary according to those who use those labels? And why do feminists attack celebs who, despite advocating for gender equality, refuse to label themself a "feminist"?
Minorities can be victims of oppression, but people who advocate for those rights don't call themselves "Minoritist" or "Asianist" or anything like that, can you see how silly that would sound? Or imagine if someone who advocates for the rights of gays calling themselves a "gayinist"? They just say they advocate for the rights of whatever, they don't have a need for any fancy label to stick on their foreheads.
(Yes they could call themselves egalitarian, but most don't see a need for any special label, they aren't obsessed with words like "feminists" are.)