People on Arfcom love to tell stories about how they go out with some old turd pump gun and kick the snob's asses. Personally, I've never seen it. Occasionally, some young kid with good eyes and quick reflexes will show up with his turkey shotgun and do OK for about half a round but pretty soon the beginner's luck wears off and they're missing right and left (and up and down). If the kid keeps coming back, it's not long before he's replace the camo pump with something better suited to the game.
And frankly, I've seen very few snobs. The guys I shoot with may shoot Brownings or Berettas but they really couldn't care less what you shoot with so long as you're safe. If you show up to the skeet field with a full choked shotgun, they may offer you a spare gun out of their trunk but otherwise, it's simply not an issue.
In my regular circle of skeet shooters you'll see all manner of shotguns: off the top of my head, I can recall a Remington 1100, a Russian Baikal, a CZ, a couple of SKB guns, a few Brownings, a couple of Berettas and even a Ceasar Guerini. The guy with the CG is just as likely to show up with an old Ithaca 37 or Winchester Model 12 pump. One guy shoots a 120-year-old L.C. Smith hammer gun. One guy who shoots a high end Beretta in one round may shoot an old 1100 the next.
Honestly, the only people who seem particularly concerned about what shotgun they're using is the new guy who shows up and is worried about what others will think. Chances are, the other guys are much more concerned about how well you tell a joke . . . the shotgun sports are a lot like golf that way. People are much more likely to want to pair up with a good conversationalist than a top shooter or a guy with a fancy gun.