No other reason, it's just that he had too little experience when he was young, and the team protected him too well.
Look at Michael Jordan!
Before winning the championship, he was first beaten by the Celtics, then by the Pistons.
He honed his league-dominating offensive skills through the beatings, and by '88, he was already called "the best player in the league," naturally, alongside tremendous booing.
He was called "the best player" because his individual skills were indeed unparalleled.
The tremendous booing, of course, was because he still hadn't won a championship!
During the time he was beaten by the Pistons, he realized his own shortcomings in physical confrontation and immediately started the first "Breakfast Club," after which his ability to take hits became even more fierce.
Later, many fans said that Michael Jordan defeated the Pistons because he had Pippen.