I know it borders on the "no true Scotsman" fallacy, but if you're anti-men you're not feminist; you're misandrist. Feminism as an idealogical position is about equality, not shifting power structures in favour of women over men.
To double down on Internet Argument Rhetoric Bingo, the Nazis calling themselves the socialist party didn't actually make them socialists. People who call themselves feminists, then try to oppress or strip rights from men, are not feminists.