These women are brainwashed when they're little girls and given (sold?) to some old man who hears Jesus talking to him about how great he is.
That's not consenting adults... and it harms women to allow this practice to carry on. Throw their religious leaders in jail and give these women the help they need.
This is the same argument I use for why I think the niqab is not really based on free will of a consenting adult and should not be allowed in a free egalitarian society.
Having said that, I get it that it's a fine line.