When he had Bernie Sanders on (who he supported), Bernie was pressured to reject Rogan's support. Guilt by association. That's how tribal all of this is.
https://www.digitalmusicnews.com/2021/04/06/joe-rogan-spotif...
I think its more controversial now only because people have leverage over Spotify - when he self hosted his show there really wasn't a way to protest. You could boycott the advertisers I guess but I don't think MeUndies and Butcher Box would have cared.
The controversy is from the corporate media and other gatekeepers now attacking him. He's the tip of the spear that is threatening their business model and control over the narrative. It's not so much about Joe as it's about elite gatekeepers vs independent media. The same fight is being waged against Substack. They just lack this kind of central figure to point at and demonize.