Randy Moss is one of the greatest receivers ever to play in the NFL. And as of today, he appears to have been cut from his team (again).
Nobody disputes that Moss is a great receiver. It's his attitude that's the problem. He's known to give up in the middle of a play especially if he doesn't think the ball is coming to him. He complains (about coaches, the team, and not getting the ball thrown to him often enough). He can make a team a lot better when he wants to, but coaches know that they can't count on him to lead by example with a good attitude and a consistent work ethic. That's why it appears that he's unemployed for the second time in three months.
A straight-A student who only participates when participation is counted towards his grade, who only talks to teachers after class when he needs extra credit, who fought with his counselor for two weeks to get his Spanish grade changed from a B to an A, and who seems to care a lot more about his grade than he does about learning the material? He's like the Randy Moss of the classroom.
Your attitude towards learning says as much if not more about what kind of student you are than your grades do. The students who teachers enjoy having in class, who teachers are happy to recommend strongly to their chosen colleges, they're often those who have the best attitudes, even if they don't have the highest grades.
A lot of receivers who aren't nearly as good as Randy Moss still have jobs today. They don't have better hands–they just have better attitudes.