Be nice to see that type of game made, just not by Bethesda. Writing has never been their strong point. Perhaps for making the terrain sure. The dynamics that make up the world and the interactions available to you though. Nah...

Problem comes from do you go down the route of having some form of "win" condition or do you just have it as a sandbox. Could be interesting as an isometric view with construction (shelter, scavenging etc)