Hold up, hold up. How do we know that he actually killed himself over this?
I'm sure that time and time again you've gone off pissed off about a little thing and found yourself becoming utterly depressed looking back at all the bad points in your life.
Maybe that's what happened here.
Maybe this just made him think about his life. And he started thinking it wasn't worth it anymore.
We know nothing of his life. Let's not judge him for now.