I disagree...it's not any different than having goo piles lying around,barrels etc being moved ,or clutter from objects being thrown around from explosions.
Something is just changing location,not that hard to do i dont think....example....say your walking up the ramp at arefu,and you walk over the wooden planks & they break,you fall down & the planks do too,meaning they just moved down,to a new location...cant be that hard to do,it can be simplifed & still be affective.....hope that makes sense

Also indoor area's load seperate to the wastland,so again this could be done.
It's different enough.
While the engine manages both objects and structural information in a similar fashion--x/y/z coordinates, x/y/z-axis rotation, scale--structures are usually made up of large pieces that 99.9% of the time don't move.
While it's possible to have a few scripted cases where structures consist of smaller pieces that do move and have their status saved, it's highly unrealistic to expect a destructive world as seen in games like BF:BC2. Not only would smaller pieces need to be used but because their status can change, every piece's status information would need to be saved. Save file size would grow exponentially, as would save/load times and the amount of memory the game requires to play. Dealing with many small pieces versus large ones will also put a very high burden on those creating content since they will both have to deal with more pieces and ensure their areas are playable despite destruction.
Comparing this kind of engine to BF:BC2 is like comparing a semi-trailer truck to a sports car. This engine is designed to support a game with massive amounts of content, most of which is static and can be returned to at any given time. It's also designed to do this without requiring players to upgrade to the latest processors and graphics cards. BF:BC2 presents a relatively tiny amount of content at any one time and once you move to the next level it's able to throw away everything from the last, since there's no way to revisit it. And even despite this limited presentation, BF:BC2 came out as one of the most hardware-demanding games.
In a way it's a classic case of quantity vs. quality. This engine is designed for large quantity with good quality. BF:BC2's engine is designed for small quantity with high quality. Current tech is nowhere close enough to support Fallout:3/NV-level quantity with BF:BC2-level quality.
Personally I think Bethesda has done an amazing job giving us the level of quality they have. This engine, though now years old, still feels ahead of its time to me.