I think it's sad in more than one way.
The kid got attacked/burned and he and his family will suffer when neither he nor they did anything wrong.
The kids who attacked him I think really believed that they were justified in what they were doing. It's sad that they have such a warped view of reality, and that they are evil enough of people to do this to someone. It's also bad that they are still free to go out and hurt/murder other people they feel they may have a grudge against. I hope they get arrested and sentenced for a long time to keep them off the streets if they can ever be identified.
I think the real culprits here are the ones who indoctrinated those teens into this mindset that white people are inherently evil and inherently deserve punishment just for being born white. I blame them for their actions, they did it of their own free will, but I also have to, on some level, blame the ones who poisoned their minds.