I doubt these boys were suspended on this incident alone. There were probably numerous incidents before the suspension regarding racist activity. I don't know about every school, but I'm certain that most schools only suspend repeat offenders. If it was on that particular incident alone (I doubt it) then yes, that was a stupid reason for suspension.
Btw there's a difference between white pride groups and Asian pride groups. I mean there's nothing wrong with Irish pride groups, it just becomes a problem when you throw in the word "white"....especially when you're in the majority. Man, I wish people in the majority would stop complaining about minorities having their own groups, months, etc. At school we have a LGBT awareness day, why in the world would we need a heterosexual awareness day? Use your brains, people.