Using the Michael Jordan vs Lebron James GOAT debate in NBA basketball, haters of one player are often driven by the fanboys of the other player. But NBA players themselves can be haters. Often it's old era versus new where you have older retired players criticizing newer eras with some evident bitterness, and the current players clapping back about how much better they are now, and players in the past wouldn't be able to compete now.

Just one example from popular entertainment, but it complicates the hater/fanboy narrative, and it's simply not true that famous successful people can't be haters (or fanboys).