This is a complicated one because Harden outgrew Oklahoma in the same way that Anthony Davis outgrew New Orleans. However, the fact remains that he left the Thunder because they wouldn’t offer him enough money. That’s fair enough because it’s a short career but he ruined it for his teammates (via Deadspin).
The Westbrook-Harden-Durant axis came to an end and the Thunder took a decade to recover. To be fair, this was Oklahoma’s fault too because it was a terrible trade and they got no value from it. We can’t be harsh on Harden here because it was the right move for his career but he was garbage when they played in the NBA Finals.