Your arguments only make sense if you assume that the people refusing to speak if Crockford is there are the bullies, while they and the organisers seem to say

Your arguments only make sense if you assume that the people refusing to speak if Crockford is there are the bullies, while they and the organisers seem to say that Crockford is the bully. Who is right? We cannot know from the available facts. If you believe the organisers' reasons to disinvite him were not "good enough" (whatever that is), well, then just don't go there or get a refund.