I think that some of the GDQ staff have started going on power trips since the event became prominent. If you show even a little bit of resistance while you're doing your run, they go nuts. They're the holy, untouchable knights promoting charity- the runners should just be glad they even have the opportunity to be there. It's not all of them certainly, but it only takes one wrong person with a little bit of power to make things go wrong. Bonesaw getting banned last year is a good example, as well as that guy who ran SMB last year getting banned for mentioning that he runs another game he was hoping would be on the GDQ schedule next time and Gamepro011 who did that cringey Crash Bandicoot run at SGDQ 2015. I mean, maybe don't let the guy do runs again, but banning him outright from the event? Uncalled for, IMO. All of these people, like you said, pay for their trip out of pocket. They physically go somewhere, they buy a ticket, book a hotel room, and practice hard so they won't screw up on stage. Getting banned from the event for something minor or a personal issue with the staff is a slap in the face.
There's logic to the rules GDQ has, but they're executed in the most exceptional ways. You need some leniency, policing things the way they do just severely takes away from the event. Banning people like Azorae (Who apparently didn't actually get banned, but the point still stands) who don't really seemingly deserve it only calls you into question when you make legitimate bans and just makes you look bad.