If you've ever stayed at a hotel, at least in the last few years, you'll remember those signs in the bathroom about the hotel trying to minimize the impact on the environment by avoiding excessive washing, and asking the guest to throw a towel on the floor if they want it washed.
I strongly suspect that this is just a disclaimer, for show, but I can't quite figure out why hotels would not want to follow this, since it also saves work effort and costs.
Fact is, based on my own experience, that this NEVER works. It has bothered me pretty much during every hotel stay that they would remove towels I did NOT throw on the floor, and when I needed them, I had to go through extra effort because stuff surprisingly wasn't where I left it.
UPDATE: Related problem: The only mild source of stress during hotel breakfast: Waiters removing my stuff quicker than I can look. I stand up from my table, walk towards the buffet, and the waiter doesn't think and just removes plate, fork, glass, napkin. They really can be over-eager.