Vince gets more of a pass because everyone knew he was a huge project (even for a QB) coming into the league. He also doesn't have a lot of weapons, but it's kinda hard to say if his WR's suck, or he just can't get the ball to them.
He's not a great QB, but he is a natural leader, which is huge. Still, I'm starting to cool on him, and a Tenn will start to get antsy if he can't take a step forward this year.