User blog comment:Cryuga/Note to self/@comment-2207258-20120415045537/@comment-2207258-20120416114035

Depends, battledome sites typically identify such an instance with Character Induced Stupidity (CIS), in which characters are unable to make full use of their abilities due to certain personality traits and characterizations. Vanilla Ice and Nijimura Okuyasu also fall under this category.

You also have to account for Dio's charisma, which is one of the many reasons why he was able to bring so many stand users under his control. Even if Arabia Fats had been able to kill Dio by bringing out his Sun, other stand users loyal to Dio (think Enrico Pucci, especially) would have killed him instead.

The site won't let my reply to your comment directly, so I have to reply to mine instead.