They already do and they're not going to stop. There's nothing inconsistent about saying, as long as they're going to block payment to certain industries, weapons whose only purpose is killing people should be one of them.
When they're wrongly refusing to process payments for ppl with ties to sex work, don't make it about some abstract principle that will equally benefit neo-nazis or CP peddlers. Make it about standing up for ppl who haven't done anything wrong & are wrongly judged.