This one had a lot of potential for walljacking, and for the misunderstanding of tone, so I say again: the response that I will not post there would have read something like this.
Again, I hear you. And I think my discomfort comes less from the practical (I'm presuming no one is deluded about that) and more from exactly the type of narrative power you're talking about -- it is, after all, what I think about for a living. I think you're right that this story is about reclaiming a sense of power, but I really don't think the thing to do with that sense of reclaimed power is to gloat, which is what this feels like. Maybe I'm being unfair, but I doubt that the average celebrant has reflected on what this means as much as you have. This may be related to comments like "Obama's probably mad that we killed his cousin," but I have a hard time ascribing that level of thought more generally. I also have a hard
time believing that it's a good idea to give all the terrorists left -- and all those who maybe weren't sure whether or not to hate us -- images of what looks an awful lot like American disregard for Muslim lives, of glee in the face of the loss of life, of jingoistic gloating and celebration that expresses far less reflection than they'd see on your wall. Because what we learned the hard way on 9/11 is that *those* beliefs and stories also shape the world. What we do will be recounted.
That said, I hope those who needed catharsis got it. I hope those who felt threatened feel safer. And I hope those who lost someone in *any* of Al Qaeda's attacks, or in the decade of violence that the 9/11 attacks were used to justify feel some small measure of closure.