Well, you learn something new everday! I didnt realise that the stationary satelites had to be so high but as your post points out it makes perfect sense.
I suppose the other advantage would be it could take a wider angle shot, less need for the stitching and overlaying of images, and less posts on PPRuNe like this current thread!
But I still standby the satelites cant yet do the quality of aerial photography, otherwise i'd be out of a job!