Seen that look before on someone as well. I've also seen some of the worse shooting there before too. Holy crap do people need to slow down and work on the basics. The target is about 5 yards away and its just holes all over the place with no particular grouping at all. I think its just the "hey, look at me shoot really fast!". Those kinda people scare me. When I go, I get in and get out. I probably send a total of 10 minutes shooting 100-150 rounds. Just empty the mag and reload... and repeat until all the ammo is gone.
The only reason I go is because it's the most convenient place to hit at lunch, when I'm in that area. And yeah, I've seen the types you're talking about and they are quite scary. The other ones I see a lot of are the ones that load up over by the bench near the window, chamber a round and then stroll across to their lane to shoot. All the while, their muzzle is going every which way.