Ya' know ... I find it hard to get worked up over this.
First, though, have to say, as far as "rehashing what the evil-doers did," I have yet to meet a single person who doesn't rehash it every single day. It's in your face, no matter what you do.
The WTC was the end of the line for a subway line and a commuter rail line, and it still says so on those trains. If you ride the West Side IRT, and you go through the stations that are still closed, you get to see the huge girders they've put in to shore up the station walls, damaged in the collapse. If you ride a line that goes over a bridge, and you get to see the NYC skyline, fuggedaboudit. I still see people start crying on the W train sometimes when it goes over the bridge.
They were literally a part of your day, whether or not you ever went to them, and their destruction is still a part of your day, whether or not it's overt. That 4yo in the playground lost her mommy on the 92nd floor of Tower 2, and that toddler never met his daddy because he was on the 100th floor of Tower 1 when mommy was still pregnant.
Can't escape it. Literally.
So BFD that the Republicans want to come in and join what is already obsessively depressingly a part of daily life.
Bush already had all the photo-ops he needed, with the megaphone on top of the "Pile" of WTC rubble, in the pilot's suit on the aircraft carrier, making speeches and sounding vengeful ... I really don't think this will make any difference.
Besides, if they haven't found Osama yet and Iraq is still messier than the mess it is today, exploitation of 9/11 might even bite them on the proverbial ... behind.
They're just going to use the convention to milk whatever emotions they want for the cameras anyway. Nothing is actually accomplished at the convention under these circumstances, anyway (with an incumbent Republican president) except enormous publicity for the party and the already-obvious candidate.
Sorry if I can't get worked up over this. Don't like thinking of my city overrun with Republicans, either. But ...

[/morose rant]