Feminism is hated because women are hated. Anti-feminism is a direct expression of misogyny it is the political defense of women hating.
The state's interest in marriage is stability. Generally speaking polygamy does not work for stability. Inherent in the whole polygamous movement is a deep and abiding misogyny and denigration of women. So polygamy is objectionable on lots of grounds.
I've been to many funerals of funny people and they're some of the funniest days you'll ever have because the emotions run high.