you've got to be nuts to not allow cropping. i do my best every time i shoot to get the best layout but most of the time it requires a slight crop to really finalize the image.
I suggest we consider the limits of what we're allowed to do to the image as if it was a printed photograph on actual paper. you can't edit it in any way, but you may want to remove that one annoying thing in the bottom corner that may ruin a spectacular shot, so you crop it.
just my opinion.
i'll have to admit that i've cropped in previous contests, since i never considered it 'editing'.