But surely the same goes for a hotel stay. What you're paying for is a room and accompanying service, there's no difference between a timeshare rental or a hotel stay.
I do not know how much is set aside for housekeeping on a hotel stay, but usually with a hotel I get daily service (which I actually do tip for). A good housekeeper will notice you are going through towels fast, are using the bath salts, or ran out of something or other and will replenish those. Even though there is no quid pro quo going on, there is no question that the tipping improves service.
Since I always pay the same per night at a hotel, I assume they have built that cost into the nightly rate regardless of my length of stay.
They are only making money on the room when it is occupied of course. I have no idea if the hotels I go to have salaried employees in housekeeping vs. hourly wages, so can't comment on if they are fairly compensated (pretty subjective, I admit). I imagine it would be harder to manage staffing levels and budgets with fluctuating occupancy.
With a timeshare,
each week has an owner paying their maintenance fee on a unit. As an owner, we may not even use our unit, and if no one picks up the inventory in II (as an example, and it sits empty for weeks),
maintenance was still paid on it even though there were no services/cleaning performed for that week. The benefit for the timeshare of course, is a steady, dependable income that is not based on occupancy. If they can pass on some of that steady, dependable income to salaried (Union?) employees at a fair-wage, then that is even better.
There was one timeshare that actually has a webpage to explain how their housekeeping fees are charged, and what happens if a week is split (requiring a mid week turnover). I assume the same would be true if I asked for a mid-week tidy -- I need to pay for that if it is not part of the standard service. It may be different for other companies, but thought it was good that this one tried to make their charges transparent. Certainly 100% of that cost does not go to the housekeeping staff, but it does make me want to know what they do get (at my own ownerships).
When you stay for less than a week then more cleans are needed for that week and the cleaning fee offsets the costs of additional checkout cleans.
www.plantationresort.com
On a pro-tipping note (with references to Marriott hotels, not timeshares specifically), I enjoyed this article from the Atlantic. A little long, but a good read if you have the time for it.
https://www.theatlantic.com/ideas/archive/2019/06/why-dont-people-tip-hotel-maids/590410/