Football players are treated like Gods around Nebraska, which goes without saying. If you've never been a student here, it's tough to truly gauge their attitudes and personas. Many walk around with a chip on their shoulder, hang out exclusively with other players and attractive jersey chasers, and take their opportunities for granted. There's a girl in my girlfriend's sorority who said Taylor Martinez sits behind her in a class, and one day said something along the lines of 'I hate these chairs - now my back is going to hurt and I'm not going to be able to practice...ugh.'
My girlfriend also took Spanish with a prominent player on the team last year, and she said he would routinely ask to see her paper during exams so he could copy.
I hear stories like this all the time, so I'm not terribly surprised when I see younger players struggling for playing time and we hear rumors about their grumblings. Many of them simply don't get it, or aren't very humble with their opportunities. Burkhead is the perfect example of someone who came in, worked hard, knew his place, and will now be one of the most memorable Huskers in history.
Aaron was probably like most freshman - came in thinking he was great, was humbled a bit by the competition, let being away from home and his comforts get to him, and he backed out. Some people just aren't cut out for this kind of thing, and it's unfortunate it takes them so long to figure it out.