The mention of honor bar charge slips reminded me of a large full service convention Marriott--I can't remember the place, but some big USA city--where the lounge attendant went around the room rudely demanding that people fill out the slips. I showed her my properly completed one in the stack and she didn't even apologize for her aggressive manner.

OTOH, I don't like the idea of giving my name and room number to be left around where strangers can see it. I always put my completed form toward the bottom of the stack or try to fold it for privacy before putting it into the container. To me, this is common sense given that hotel front desk staff are instructed never to announce a guest's room number.