Perhaps some Palestinians did mourn, and perhaps some of the mourning even went beyond a rational but self-interested consideration that 9/11 would hurt the Palestinians. But there was no conspicuous reaction in Palestine to the initial celebrations, no revulsion.
I have no doubt a minority of Germans in 1941 were active Nazis, and most Germans wished the war over. But the fact is, that when you're at war with Germany, the fact that all Germans don't hate you is irrelevant.
Bluto-Animal House