Please note that my comment wasn't some generic statement about all hotels. My comment related to a specific hotel. I worked there for over 8 years...starting as an hourly employee and ending in management. Trust me when I say that all the managers knew that union contract backward and forward. Nothing was "at the discretion of management". Any time the contract was broken, the union filed a grievance.

Also, in that hotel (and another hotel where I worked during a soft-opening) the housekeeping staff working at night were all promoted from within. It was considered a promotion because they had minimal supervision and had to know how to do virtually all the housekeeping-related tasks (room cleaning, turndown, laundry, pressing, and public-space cleaning). The position also included a healthy bump in pay. They might not have been quite as fast as the daytime room cleaners, but they missed anything when cleaning a room.

(Finally, I'm not trying to hijack this thread with pro/con union arguments. That hotel union was horrible. But, in another job a few years later, I voted 'yes' to a unionization effort. So, I've been on both sides.)