He's one of the best ever, but he's a complete clown.
The guy abandoned the championship for stupid reasons and let down the American people, who were ecstatic about having an American champion beating their enemies at the time of the USSR.
He could of kept defending his title and complaining about the system as he did it, but instead he chose to abandon it. I cant respect someone like that. Magnus kept defending his title despite talking about the problems with the format and the lack of prestige the championship was getting from FIA, but he kept playing until he saw the FIA wasn't listening to him.
While it's true his reign at the top was brief, the sheer, crushing dominance he displayed over the world's best players en route to the 1972 championship was an achievement that many feel is unparalleled in chess history.
Can you ask ChatGPT whether Magnus Carlsen or Bobby Fischer would win a 10 game match with Armageddon tiebreaker?