Simple, attention... or to just mess with people.
Did you know that Trevor was actually set to be in a "gangster" clique that were similar to dropouts, but did a lot more crime? They actually had an animation to hi jack cars only used in the beta. They thought this was too much for the game however, so they changed him to just be a boring student since part of his body was already done. Just had to change his uniform textures. Also with the criminal gang came a knife weapon, pretty crazy right? It's pretty obvious why they were taken out...
...no, you didn't know that because I made it all up to prove how easy it is to make some shit up. Not calling Tyler a liar at all but, just saying the possibility may be greater then you think.