Call me crotchety, but I'm sick of seeing tourists in a big city dressed as if they were visiting Disneyworld. And it might just not be tourists either. This includes those who should know better (ie anyone my age).
While it hardly ruined my vacation in Chicago (a great city by the way), I was greatly relieved to see that the crowd visiting the Art Institute had all Made an Effort.
This is not to say there was a fashion parade going on. It wasn't the Met Ball, nor should it have been. People were dressed appropriately (and comfortably) for enjoying the art and being in that great space.
I even saw a young woman evoking Audrey Hepburn and looking as lovely as the art herself.