Here's a "tip" - only tip if you feel the need to.
A tip, by definition, cannot be required; at that point it becomes a fee, something entirely different from a tip. I give a tip voluntarily; I pay a fee b/c I am required to do so.
I tip waiters/waitresses, b/c that is a tipped position. I don't leave 15% regardless, with extra for good service. I begin the meal with a tip of 0%, and work my way up from there. If you keep the drinks at the table filled without me having to ask you, or if you leave me a pitcher of what I'm drinking so I can do it myself, you've earned 10%. If you check back (often) to make sure the food was right, that I don't need anything else, etc..., you earn another 5%, for a total of 15%. That's all I ask. If the food comes out slowly (whether or not it's your fault), your tip % goes down, unless you are apologetic and maybe actually explain what the problem is. It's not my problem that the 2nd cook didn't show up; my tip doesn't have to adjust for your restaurant's problems. I think a good waiter/waitress would be getting their manager to comp me or at least come to the table and explain that there's a problem. If you do a great job, and food is on time and correct, you'll probably get 20%. If you do a poor job, and you're not apologetic about it, and the food is slow, you may get 5% or even less, depending on how snotty you are. I'm not tipping you b/c I ate at the restaurant, I'm tipping you b/c of the service you provided WHILE I ate at the restaurant; I think there's a difference.
What does this have to do with tipping Mousekeeping? Nothing, b/c it's a NON-TIPPED position, so the point is moot. You were hired to clean rooms as a non-tipped worker, so you are expected to clean rooms as a non-tipped worker, and I will not be guilted into tipping you, or anyone else for that matter, unless I feel like it. I can't afford to tip the maid, the waiters, the person working the cash register at the Winn-Dixie, the person in line behind me at BTMR...I don't have that kind of cash! Wait staff, maybe a bellman or 2, that's about it for me.
Flame away.