One reason to actively oppose DHH is that he actively opposes anyone who calls him out, going as far as squashing valid criticism at his own company and ousting them from positions in open source projects (the whole ruby central case).

Even if you don't think he's a nazi, he's shown himself to be a bad actor who doesn't play by the rules.

That's also a kind of behaviour that leads to community vibes going down the drain and other bad actors (nazi or not) taking over.