I want to be careful that this stays away from a discussion on tipping... I've seen those get out of hand!
Having said that, I actually agree with you -- pay people a good wage and reserve gratuities for TRULY EXCEPTIONAL service with no expectation otherwise.
Additionally, I also agree that the ability to easily add housekeeping gratuities to the folio would be a great convenience -- probably for everyone involved (except for those employees who currently choose to underreport their gratuities to Uncle Sam).
Having said that, there needs to be some established, brand-wide policies regarding this:
1) Such a system would have to be opt-in by nature, with the ability for the guest to choose whether or not and how much to tip housekeeping.
2) Clear assurances, possibly with corporate audit, that the gratuities are actually going directly to the housekeeping staff, and are not merely used to supplement the hotel's payroll expenses.
3) An explanation as to whether these tips are pooled and divided among all service staff, or all housekeeping staff, or simply to YOUR housekeeper.
4) If a multi-day stay, an explanation as to whether the tips are divided among all housekeepers who served your room, or go to the housekeeper who serviced your room at the end of your stay.
5) Clear communication about whether or not gratuities added to the folio are taxable, and whether or not they qualify for HH points.
(I want to be clear -- I'm not opposed to paying housekeeping staff well... or even tipping them well. I AM opposed to undisclosed, automatic tipping.)