[quote=@Natsucooldude]
GMs that take on a bunch of players and then wait for absolutely everyone to post before doing anything at all.
[/quote]

This. So much this! I've noticed it a lot lately too. I can see the RPs in my Sub Box just sitting there and I'm like "So...we got our characters made. You gonna do anything?"

What annoys me to is when the GM doesn't post regularly to see if progress is being made. Just a simple "People still interested? Need help making your sheets?" and that's it. I've seen and had to drop RPs for this because the GM decides to not update anyone anymore. It's not up to the players to get a game started.