Marvel screwed him over.. Jon Favreau had problems with them as well that's why he didn't direct Iron man 3 or The Avengers flick. But he's basically lashing out at RDJ because of how successful he became after the first Iron Man movie.
I will say this... Terrance Howard was a waaaaaaaaay better Jim Rhode than Don Cheedle is. Terrance was actually familiar with the character from the comics while Don Cheedle had no idea of the character and it shows when you see the chemistry between Stark and Rhodes in the movies.