I believe that there is merit to both the argument of AR-firepower and bolt-simplicity. The point is that they are not mutually exclusive. If we are thinking from a "one-gun to survive", the GSR makes sense. If we have choices, semi-auto is hard to argue with.
But then again, if society changes for years, simplicity might be a plus. If parts and gunsmiths are hard to find, the bolt-action sounds better. IMHO.
Si vis pacem, para bellum