I spent 30 minutes investigating this mystery as well, and the best I could arrive at is that this has something to do with politics but no one actually wants to expressly describe the exact positions held or why they are naughty.
It's more than one reason, and it's not just political views of the person who really wants to do the keynote. Though the replies to this thread help explain the position many who are leaving are in right now: https://twitter.com/kaspth/status/1499431981830086657
Whether DHH is a dick (he is) or at times a diva, he’s literally none of the things this Twitter account is trying to label him as.
To call him far right is ludicrous, and pretty much the exact absurdity he’s often writing about in regards to people being unable to handle any differences of opinion anymore.
The leap to “you disagree? Nazi!” is why we all need to quit Twitter
I appreciate you trying to be helpful, but I can't make anything out of that twitter link. The only thing I can gather is that maybe DHH tweeted about this developer? Or that DHH worked with this developer but didn't give him the full context of what they were working on together?
Contributors are being publicly brought up in drama posts wherein one of the other main contributors seems to be happy to implode the community in order to continue as a BDFL figure, despite that the community is at near consensus that he doesn't deserve to keep that position as someone who keeps becoming increasingly divisive and whose contributions have grown more minor every year.