I'd say they have enough integrity to not support a parent organization that has made an odious decision.
There's a different between "allowing someone to speak (anywhere, at all)" and "providing them a platform." The parent org has decided to provide a platform, which has consequences.
You can disagree about the decisions made, but your "belief system so fragile" is a strawman.
Nope, not about fragility at all. It's about creating spaces where a large chunk of people aren't being literally attacked (and told they are better suited to being slaves) by a speaker. What's the problem? Free speech can also mean no speech. I have no problem with people pulling out if they disagree so strongly with the social views of another participant. This isn't the government smashing someone's printing press, this is people voluntarily deciding not to share the stage with someone whose views they abhor.
Nope, talk content doesn't matter. If I know you believe that "rape doesn't exist" and you regularly publish about it, but you are giving a talk on 'advanced garbage collection in Ruby", I can still feel totally ostracized from the conference knowing what you've said in other spaces is literally an attack on my safety.
There's a different between "allowing someone to speak (anywhere, at all)" and "providing them a platform." The parent org has decided to provide a platform, which has consequences.
You can disagree about the decisions made, but your "belief system so fragile" is a strawman.