Urban, there's nothing wrong with banning booth babes. According to Dan's definition, they're just models hired to be there and look pretty, not knowing anything about what they're cosplaying as or where they stand. I can see why this isn't needed at an event such as E3. To most journalists, they're a sleeping Snorlax and in your way. I can see how this could be a problem if you're trying to get coverage of a game.
Now, if they were there to actually talk about the game and give detail about who they are, that's different IMO.