Yes, it's repairable. I'd do it by riveting some thin aluminum where the mount clip nuts were, and then pop some new clip nuts on. A better question is just how it got broken. Is there any sign of scuffing, or were the fasteners just really overtightened?
I don't know. I've had the car only since March, and the cover just came loose. I expected to find broken pieces like clip nuts, black plastic remnants of the brackets that broke, but nothing. Weird. Maybe, just maybe, it's been loose like that since I bought the car, but never was displaced enough for me to notice until yesterday.