While I agree that he is an exceptional person and was an exciting player to watch, part of his problems stem from his weight gain. If you notice, he can not lift his leg as high as he used to, which has reduced his movement and velocity. He needs to get that back under control before he will get better.
As much as I like him, I am very glad that the Mets did not get him!
I totally agree with Legalbgl concerning the weight and control issues, but it's kind of an insult to send Dontrelle all the way back to single-A ball. Going to AAA or AA would've sufficed just fine. In recent years, Dontrelle has been one of the most exciting pitchers to watch and his high leg kick makes me think of a left-handed Juan Marichal. I hope the D-Train reverts back to his old form soon.