I was about to say, no it doesn't... I still can't think of a single true freshman QB to start and lead a team to a title, I'm waiting for someone to give me an example.
To answer the general question, some people were wondering if Barnett was ready yet, and that sort of thing for a little while. He goes out and plays a scrimmage, he throws a couple of picks. No big deal, but it just shows where he's at. Then, even the video of him running into Henry, while funny illustrated that he didn't know how to position himself yet. As has been mentioned, we're talking about SEC defenses, they can make almost anyone look bad. There are so many little things he has to learn, not to mention general mental and physical development.
Let me give one example, people say Barnett has speed so he can get away from defenders. That's all well and good if he sees them, but if he drops back and he doesn't feel the pressure coming, he could get blind sided. Or, he does feel the pressure, he tries running away and gets leveled by an up-field defender. He needs to bulk up, he needs to learn, I believe in his talent, I've said that all along, I do think as a redshirtfreshman he has a chance to start, but I don't see him as the solution to the problem, I see playing him as causing more harm than good. If the coaches thought otherwise I'd defer to them, but the Blake Sims (not a popular pick with the fans but now we can clearly see he was the best option) thing last year reminds us that they kinda know what they are doing with the quarterbacks.