Since i liked
Adinho theory, let me give you a scenario.
Troy was gay, maybe he was kicked from the Alphas for it, maybe there was some other motive that we don't know yet, but after that, the dude was pissed. If even before being kicked from the frat, he was already Chad's gay lover can you imagine how frustrated he was? Obviously he could understand Chad and all he could lose if he came out, but... Remember when the Alphas attacked him and took MC's guitar? Troy was beat up because he probably tried stopping them.
That was the final straw, he had to do something. In a mix of frustration and desire for revenge he starts his plan to throw shit into the fan. Things escalate, but end up better for him, since Chad is now out of the Alphas and they can be together without too much drama.