He wasn't rude, just not at all interested in making conversation. You know how it is, you walk up to a booth, and either the person working the booth will come up to you and initiate conversation, or at least catch your eye when you're looking around the booth and at them...he didn't do any of the above so I figured why bother.
Maybe he was just hanging out and not working the booth, but if someone's behind the counter, you naturally figure they're representing the booth.
You should of said something Steve. Maybe you should of stuck around longer and came back, perhaps the alleged "unapproachable" guy would of engaged in conversation with you. Go shoot him a PM if it bothers you, you must know who it was by now.