Out of pure curiosity, what's wrong with him? I don't feel his vibe so I never got into listening to him, but I was under impression he's popular and quite liked.
I dislike his interviewing style, in that I think he reliably lets guests just make assertions that go unchallenged. (https://www.vice.com/en/article/9kv9qd/the-joe-rogan-experie...)
I find this particularly problematic when he's having "provocative" folks on; it gives them an enormous platform, and one that allows them to get Rogan to nod along where another interviewer might push back on readily debunkable things. We've substantial research indicating deplatforming folks like Alex Jones is effective at reducing the impact of their misinformation. (https://www.vice.com/en/article/bjbp9d/do-social-media-bans-...)
There is zero "substantial research" in there.
There are actual studies on the impact of Reddit deplatforming, specifically around the /r/fatpeoplehate and /r/coontown bans. http://comp.social.gatech.edu/papers/cscw18-chand-hate.pdf
As to the paper, I think you can poke a lot of holes in it. For example, AFAICT they found that hate speech went down, measured via the frequency of words commonly used within these subreddits. Certainly much of the decline is then attributable to the subreddit's subculture getting killed, and taking with it their slang words. It might just be that other words are in fashion now. And it's not a given that this even generalizes from deplatforming subreddits to deplatforming individuals.
So I still think it's a stretch to call it substantial research, but without getting hung up in any more details, I think the fundamental effectiveness issue with deplatforming is that by taking away the platform, you don't change people's opinions. You just won't see them talk about it anymore, and that's you as in you, the one who banned them, and no one else. They'll still be out there. It's just that now, you're sticking your fingers in your ears and going lalala (this is also mentioned in the paper). See the democrats losing to Trump in 2016 even though basically the whole mainstream media demonized him and his supporters.