No, I don't understand them and I do blame them. Those who act like beasts, deserve to be treated like beasts. The problem with those guys is that they're mentally ill. It's not the fault of other people that they become like that. It's because they have no spine whatsoever. If everyone is as weak as Cho Seung-Hui there would be so many shootings at high schools.
To be fairly honest, I'm a bit worried about you, chinafan. You hate the system, think that love doesn't exist and you can understand beasts like Cho Seung-Hui. Perhaps you should have a chat with your parents?