I've happened upon this scenario in Wal-Mart a couple of times. The first time, it was actually quite a shock. I literally laughed at them. They looked at me all puzzled. For a moment, I thought about pulling their battery cables while they weren't looking, just to see how long they would sit there 'stranded'. I was thinking that one of them might get on their cell phone and call the service desk to ask for a tow. I have no issues with people that have actual injuries using these things. 90% of the time the people I see using them are clearly just too lazy to walk around. If they REALLY NEEDED those things, they would already have a wheelchair or something of the like.
Nah, lots of temporary injuries, surgeries etc make the scooters really attractive although there is no real need to lay out the bucks for a wheelchair. Being a mountain biker, and having suffered injuries common to the sport, I've ridden many a scooter at the grocery store with a cast sticking out like a lance. I was always on the lookout for a similar individual so we could joust, but never found one.