Yay's problem was that he actually thought he was a good player when he wasn't (and he wasn't wrong for thinking that tbf, most ppl and fans and insiders still thought he was one of the best players itw).
Imagine thinking that you are a top player, playing in a T2 league and getting outclassed by (basically) nobodies.
I would've tilted as well.
Time showed that he wasn't a great player after all. But can you really blame him?