This was not "their civilization" - it was rather the common heritage of humanity. No doubt there's more in the ground to be dug up.
This experience demonstrates why antiquities should never be left in just the home country - as discovered they need to be spread around so that a single event can't destroy all of the materials.
The looters will probably take as good care of the antiquities as did the museum keepers - maybe better! All we have here is a change of ownership - not the destruction of the materials, and appropriate funding plus information from the catalogs will enable the exhibits to be put back together (in time).
There is a gold museum in Peru that contains looted treasures and it is of some historical value but not nearly as much as if they knew what regions different items came from.
I will say this. Ancient Jewish temples are being plowed under in the Middle East with no thought to historical preservation. Either cultural past has special regard or it doesn't, the journalists don't get to pick and choose.