My pet grumble is GM's who create exceptionally detailed sandbox towns to play in with various plots of interest.  The players ignore said plots and turn into 1-1 hook-ups.  Inevitably player attrition develops and you have a bunch of people lost, in need of a cold shower etc.  Meanwhile, the GM who put the place together initially effectively gives up on helping others make the place interesting.

Perhaps the flounce was in response to everyone going to the corners to cuddle rather than interact with the setting...