Wynton started out with Blakey's Messengers, and everybody said he was arguably the worlds best trumpet player. That could still be true because he also plays classical music. While he might be the best jazz trumpet player, that did not include being the best jazz musician.
After Wynton left Blakey, and was on his own, the shortcomings in his jazz composing talents became apparent. But he also plays classical, and that bumped his stature up with the establishment.
https://wyntonmarsalis.org/videos/view/ms.-b.c.-art-blakey-and-the-jazz-messengers-live-at-seventh-a...
There, Wynton is playing the hippest of the hip jazz, and he's blowing it out of the park.
Criticism of Wynton from Aficionados and other jazz musicians did not come along until after he left Blakey. That's when we discovered he wasn't as good at making his own music as we thought he would be.
That's it in a nutshell.