This article explains why Durant has made a right decision

The fact Reggie couldn't get a ring still bothers him this day. Because he will always be identified as the Reggie Miller who was a good player but just couldn't bring a title to his team. That is a deeeep wound. I guess Durant doesn't want to suffer the same fate. The so many "I get it" in Reggie's article explain exactly why Durant has made a right decision for himself.