The existence of rockstars provides fodder for individualist ideologies. Many people are more collectivist, so therefore feel the need to dispute the existence of rockstars. This is a little bit evident here - you need a rockstar team, with diversity. It's far more evident in the last post on this same topic.
(Not quite a dupe, but it might as well be. https://medium.com/about-work/6aedba30ecfe )
Amusingly, it's also a very corporate philosophy. "No programmer is worth more than any other, therefore to advance you must enter management." Tends to be self selecting in such corporations, since everyone who isn't mediocre leaves.