You just answered the question. Crumple zones are stopping distance. Greater stopping distance lower the G forces on the occupants. The Suburbans will look a lot better after the accident (with that solid bumper bolted to a rigid frame.) Crumple zones and more strict safety requirements for passenger cars, compared to Trucks (including most SUVs), favor the drivers in the Camrys.
Paul, I think you're confusing crumpling with survivability... these do not necessarily go hand-in-hand. To bring this to the extreme, build a car out of aluminum foil. Now run this car into a Suburban, with both vehicles traveling 50mph... yes, the aluminum foil car will have crumpled, but not enough energy will have been absorbed... the person in the foil car will still be dead. I view subcompact cars as not much more protection than this hypothetical situation, and the numbers of deaths for those cars... Neons, Prisms, Metros, etc. substantiate my view.
-Norm.