Don't laugh, but waiting for marketing is entirely possible here. If demand between now and the first 787 deliveries is going to continue to suck, it could very well be a stronger business case to take the insurance money and part it out, especially if it's got a high residual value.
Fixing it "just because" is something QF did when they put a 747 into the golf course next to the BKK airport. They spent more than the write-off value repairing it, in part due to the "Rain Man" image of not having had a hull loss in modern times. AA unfortunately can't make that claim.