Meh. The major he was hosting had a TON of problems, terrible organiser and no doubt the worst high profile esports event of all time.
Pretty much everything went wrong, from technicals, to bad service for players, off stream games, people having to leave venue early, sound issues, everything. The dude had a tough job filling a ton of time as host and on top of that he got a lot of the blame of the organiser's problems on him, despite having nothing to do with it.
According to his side of the story, which does give a lot more detail than Valve's side, and makes more sense, he was fired despite being told to be himself on the show, and that's apparently why he was hired in the first place after a year hiatus. He was himself, did the same things he'd done at previous events, which mostly had been successful, and then he got fired after 2 days. The community loved him though, sure there were some people who disliked his unprofessional style, but the vast majority of viewers enjoyed him as a host and were against firing him.
If you do some research into it, you'll find that it sounds heavily like Gaben himself got triggered and fired him. It doesn't seem to have been a mutual decision, just Gaben. Obviously quite unfair, he may be the CEO but considering he contributes absolutely nothing to the esports scene of any of Valve's games nor the development of them, he shouldn't have the power to fire a personality during a tournament.