My opinion is that his future with OKC looked bleak, especially with the recent trades. I guess his ambition to win a championship was more important than leave empty handed year after year. Knowing how players are typically judged by their rings, it's a no brainer on KD's part really.
Now I'm eager to see how much he will be demanding of the ball or will he accept a role similar to Aldridge. Hopefully Bogut is well and healthy come next season. In either case, this team should be fun to watch.