There are more than enough things to complain about. If somebody wants to have a YouTube channel where they just complain, why is that a problem?
Personally, I have never seen anything other than complaining from him, so I'm not sure why you would be a fan and also have a problem with the amount of complaining (which afaik has always been close to 100% of the content).
Because the complaining isn’t as fair and balanced as he presents it. He likes the stir the pot and he spreads misinformation along the way.
It’s a problem because he has a wide audience of people who adopt the anger that he puts out and accept it as ground truth. It’s a smaller scale version of people who get their opinions from people like Joe Rogan, who fill their time with misinformed rants.