And yes, he is a massive asshole, at least in regards to chess. He is an incredibly sore loser, constantly makes it about himself (at the cost of every other competitor, such as in this case: they can't have beaten him, but instead he had to do this spectacle to give himself an excuse to exit and to asterisk their win). He has done this sort of thing again and again.
He has loads and loads of fanboys who will always excuse this behaviour. Who'll say that he has earned the right to be like this. They'll adulate poor sportsmanship like showing up terribly late "like a boss", as if this isn't contemptible behaviour. Eh.
And he can. He might be the greatest chess player ever. Doesn't change that he's obnoxious and boorish.
The reason why Magnus leaving is a spectacle is because of us and what we want out of our superstars, otherwise he's just another player, and players drop out all the time for any reason and nobody cares.
The masses are the ones who elevate him and assume that because he plays a game so well then the spotlight must be on him. Magnus did not seize the spotlight of our attention and he never owned it.
No one is asking him to act like this. Many other greats across many domains manage to not be like this. His performance alone gets him loads of attention, and this is all just distractions.
And yes, people do drop out. It happens. Magnus is famously a very sore loser, however, so when he suddenly is a Dress Code Liberty Fighter to drop out, it should be called out for the ridiculous ruse it is. That people are actually celebrating it and talking about his principles...how profoundly gullible can people be?
The guy has an insane number of fanboys, however. It's absolutely bizarre.