I don't think anyone here said it was offensive nationalism. And, as others in this thread have said, it's not quite clear why the school originally asked the boy to not display the flag on his bike so it's quite a stretch to argue that that was what they were thinking. You're making a lot of assumptions here, Rush, that others might find insulting.
Actually, quite a few posters have said that nationalism is wrong. It is also quite wrong when those of opposing opinion keep saying "there must be more to it than reported" for the ban to occur.
Yes, of course, nationalism is wrong. Do you seriously disagree with that? How can thinking yourself superior to someone else only due to where you were born ever be right?

If you had read my post more closely, you would have noted that I said that no one in this thread has called what the boy did offensive nationalism (because it isn't), which was what
Rush seemed to imply. Apparently, he just went on a rant only very slightly related to the topic at hand without telling us but I thought he was commenting on it.
And how can saying that there probably is more to the topic be wrong when the school actually hinted at that in its statement?
Rush's rant implied certain motives for the school's action which aren't really in evidence from the few facts we know about this. So I pointed that out.
Personally I find any organized chanting of oaths, pledges, hymns or prayers very, very uncomfortable to watch and listen to.
Not a sports fan, I take it?
The national anthem is hardly ever played at sports events here.