I guess few countries do patriotism quite like the US does. The British are patriotic, but in a much more... relaxed way. We take the piss out of our own nationalism in a way America doesn't seem to quite understand, and we don't understand their more clearly fervent devotion to their country in the same way.
I don't think 9/11 is "not worth the fuss", and it's not unfair that it's still a major wound for the US in its national psyche. I can see an argument that the prominence the US gives to it gives its enemies more incentive to try and twist the same knife, though.