Herb Sutter's article shows why this is actually a big problem in practice. He has an example of a class containing a guaranteed-non-null owning pointer. Leaving an object of this class in a "valid but unspecified state" means when you move out of it, you'll have to replace the internal pointer with a pointer to some new allocation, the very thing move semantics is supposed to help avoid. He suggests that such a class should simply not be moveable.

So the fact that moves are not destructive is indeed very limiting.