Because we all have to get along regardless of what you believe and DHH hasn't advocated for violence against anyone. You can't unperson everyone disagreeable, especially relative to their contributions in the Rails community.

Notice I said Rails community, not Ruby community. Not letting DHH speak at RailsConf is like barring the Pope from the Vatican. There are a lot of big new changes in Rails this year that he has been championing. He was absolutely the right person to give the keynote.