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.
In New York everyone's desperate for success desperate for money and desperate to be accepted but in London they're more laid back about things like that.