This excuse is akin to a thief saying they are poor, or a rapist saying they were horny - they don't excuse the behavior
I don't agree with the killing, but I think these comparison are really bad, especially the rapist. The one bullied is also a victim, but they shouldn't have resorted to killing. If I relate it to grownups, it could be a neighbor harassing another person. People will usually escalate to the police if talking it out doesn't work. But if the police [teachers] don't do anything, some take it into their own hands.
Being a kid, they didn't have the maturity or experience to handle it in a better manner. I would put the blame on the adults around them; the teachers and parents. I hope all the kids recover from this.
Making victims of others to meet our own needs, is never appropriate, is it? There is no good excuse for violence, but if we keep relying on other people to step in so we don't have to manage our own emotions, we will never learn how to. We need to stop expecting an authority to protect us.
Never said it was.
In an ideal world, I agree. What if a terrorist group, mafia, or gang are troubling you. Police or the government are your only logical choice. Unless you want to go Rambo on them, then you will just be like the kid.