The reality is college players are not ready for the NFL, some positions the learning curve is greater than others. For O linemen, especially LT's, its a bigger gap than other positions. For NFL teams, that makes it a bigger crap shoot. They have to go by what scouts "predict" an OL ceiling is. Look at other NFL teams and you see that a lot of them are having the same problems fielding a decent OL. Same with WR's, they just aren't taught in college what they are expected to do in the NFL. Fans are just going to have to get used to the idea that top draft picks are not ready to play day one, and that one training camp isn't enough for them to learn a massive play book and all the complicated plays. Some may never learn. Look how long its taken Brian Quick. GRob is progressing, its going to take reps for him to become instinctive. He's stlll getting new looks he's never seen before, and he's going to get fooled.
The sad fact is, over the last five or six years, major colleges have been changing they way they play football, spread offenses, where offensive linemen don't even put a fist on the ground, simplified play books, simplified plays, (everyone go deep, I'll throw it to ever is open). Its unrealistic to excpect a guy like GRob, who came from Auburn, where he never put a fist on the dirt, never got taught the art of pass blocking, to learn all of that in one or two seasons.