"The maid would stack my loose change every day by denomination."
That's a far cry from the 2 or 3 times I've left my pocket change out and had it disappear. It's not like I don't tip the cleaning crew. I tip rather generously, but do so on the last day of my stay. I see two rationales for the disappearing coins:
1 - They know they can get away with it and don't care (sad)
2 - They honestly think that this was my tip to them (even sadder)