That does sound plausible but I do know. When I come across suchlike justifications for petty rules, I rather tend to feel there's some kind of petty control frreakery behind it. Then again I have no military experience.
Requiring them to make their beds doesn't strike me as unreasonably petty, and to the extent that they do make soldier follow petty rules it's often done with a purpose, usually to install obedience. Not that there aren't lots of dicks in the military, but you shouldn't be so quick to dismiss the way organisations do things because often there's a good reason.