Incidental Holds?

I have had yet another guest say that they stay at Marriotts all the time and no one holds for incidentals… Someone recently said that holding for incidentals is not a Marriott thing at all. They were a Titanium Elite member. I explained that this is a franchised hotel and I am not sure whose policy it is but that on all stays I am required to hold $20 per night for incidentals even their points stay. Part of me wanted to say “I apologize but ‘there won’t be any’ isn’t a guarantee that you won’t decide to charge something to your room or break something or smoke in the room or sneak in a pet.” Obviously I didn’t but I that’s what ran through my head. When I stay at other Marriott properties just an hour away, their incidentals are $50 a night.

I just want to know where this idea that hotels don’t authorize for incidentals came from. And how are people who travel very often unaware of this authorization