My pet peeve would have to be not enough time to quilt, too many other day to day things get in the way - guess that's life.
My #1 peeve at quilt shows is the little pieces of thread or fluff on quilts that are hanging - my fingers just itch to pick them off. I'm sure it wouldn't take someone long to go around and check each quilt after it is hung. It seems to be the first thing that draws my eye to the quilt.