If you get to talk during judging, tell a band that you don't like that their influences are too obvious.
If they fight you, tell them that if they're influenced by any bands who actually got around to pressing CDs, they're unbearably pedestrian.
Real bands are only influenced by bootlegs by bands that only existed for one show, thirty years ago, acquired by decipering the secret code in zines.
Make up a bunch of silly band names and place them all in known college towns and tell them what they're supposed to be listening to and emulating.
"Oh, for God's sake, gentlemen, get your hands on some of The Filch out of Chapel Hill or... Voluminous Thump from Ithaca back in the Eighties or... Christ, even something introductory from back when Steve Zilla and the Klu Klux Kongs were in their Austin days. For God's sake. For God's sake. I bet you people appreciate Saved By The Bell in an unironic matter."
The Simon Cowell of scenester douchenozzles would be the best character ever.