LaBeouf LeBusted

I would imagine Spielberg anointing you to be the prohibitive new face of the franchise would get inside a young guy's head, especially if the young guy is already a douche.
LaBeouf hurt his cause when he began popping off in the media about the suckage of Crystal Skulls.
A 20-something actor with a limited catalog can't be seen ripping his own movie in public.
He embarrassed himself, his co-stars and his prolific director, and it's no surprise his career has been circling the drain ever since.

 

He also ripped Michael Bay publicly. Not the first to do so, and he may have had a point, but I'm guessing if he kept his mouth shut, he might still be involved in the series.

Ripping Crystal Skulls killed him though. I think he may have even made those comments either before or as it was coming out, which is a colossal no-no in Hollywood.