I could understand someone unzipping early to make things move along faster if they have to go badly. I've done it myself. It's just so that as soon as I step in front of a urinal I can hurry things along. I think more guys step away from urinals without putting everything back in it's rightful place. I see guys step away from the urinals quite a bit and start walking and they haven't even tucked their junk back into their underwear and pants yet.