It is very much because of gender. If you google 'bernie sanders laura jane grace' you will find nothing but outrage-farming by all the usual culprits. If a cis musician had done this a few bigots might have whined, but the right-wing outrage machine wouldn't have chosen it for their Two Minutes' Hate.

Laura probably knows they're gonna come for her anyway, might as well be aggravating about it. That feels pretty damn punk to me.

P.S. no masters and especially no gods