I like Joe Rogan, and I think there's a handful of reasons why people love him so much:
1. He has strong principles. This is evident when you look at his involvement in the downfall of Carlos Mencia, despite being a relatively unknown comedian at the time.
2. The only filter is himself. He's not a part of a network, and thanks to you "fuck you money" he made from Fear Factor he doesn't need to answer to anybody. That allows him a level of independence to have who he wants on his show, and to talk about what he wants.
3. Passion. I do BJJ, and a lot of people have got into BJJ through Joe Rogan talking about it on JRE. It's funny how much of an impact he's had, considering there is very little footage of him actually sparring. For reference, he's got two black belts - one under Jean Jacques Machado in BJJ, and one under Eddie Bravo in his 10th Planet style of BJJ. Both instructors are as legit as they come, and they don't just hand out belts, so Rogan earned those belts. His passion for BJJ and MMA earned him his spot with the UFC, and a UFC post-Rogan will be a much-worse place.
4. He naturally leans to the centre. It's funny how some people on the left call him right-ring, and some on the right call him liberal, when I'd say he has individual views on multiple sides. He'll have a civil chat with Bernie Sanders on one episode, and will praise Trump for playing a good campaign against the Democrats on another. It's refreshing to see someone open his airtime to multiple different views, when even the likes of the BBC cannot represent both sides of a debate without extreme government bias.
5. He knows what he doesn't know, and he won't convince himself of something without fact. That attitude in a sea of people that push opinion as fact is refreshing.