This addresses two issues. First, when a group is working together to build a parcel, it is often convenient for one builder to be able to move another builder's work in order to make space or adjust the general layout. But we generally do not want to make our objects movable by anyone, and may not want to give the rest of the group permission to edit or move our objects more generally.
Second, in many parcels, particularly in roleplay environments and sandboxes, general (everyone) group members or even the general public are allowed to rez objects. It becomes a parcel administrator's job to make sure the objects rezzed are appropriate and appropriately placed. Often the administrator will approve the object, but not the location. In this case, rather than returning the object and having to discuss with the owner appropriate location, it would be much simpler for the administrator to simply move the object within the parcel to a suitable location and then inform the owner of the new location. For me, and the hangouts I administer, this is often a few meters, and can also be something I may do several times in the course of a day as I "rearrange the furniture" so to speak, for whatever activity is going on at the moment.
Finally there is the question of encroachment, when an object centered on a neighboring parcel intersects the parcel under consideration. In this case, having general move-the-object-in-its-parcel power is not appropriate. Instead, if anything, I would suggest a related power, the ability to simply cause the encroaching object to move the minimum necessary distance into its parcel to end the encroachment.
As discussed in the SUG meeting, allowing Estate Owners to mark objects as Estate Content, akin to the existing Linden Content flag, and preventing objects so marked from being returned or moved by parcel owners or their group designees would probably be a desirable feature.