I shot Seattle's burlesque scene for about six years before stepping away two years ago (you can see my archives here: http://www.flickr.com/photos/csb13/sets
) and I'm with Dan and @5.
Burlesque is odd in that there aren't many signifiers beyond some venues like The Triple Door to let the audience know the quality of the show. As a result, you have performers with years of experience before they started doing burlesque (Waxie Moon, Can Can Cabaret, Lily Verlaine, etc) lumped in with performers who'd never taken the stage before attending a class (too long to list). So the audience can run the risk of being disappointed in a way that isn't likely in, say, ballet. Unless they missed the sign reading "Miss Johnson's First Grade Recital", of course.
I heard something like this at one of the last shows I shot, when one of my neighbors leaned to her friend and said "That was... interesting?" as the crowd applauded. No doubt they were expecting a fantasia of feather fans and sequins but what they got was a girl flouncing around the stage for three minutes in an amorphous setting before taking off her top. Tah dah.
At its best, burlesque can be amazing. At its worst, as Dan said, a girl just has to be willing to take off a dress.
Are people blasé about burlesque? I don't think so. Are they finding their standards? I really hope so.