Originally Posted by
OskiBear
As others have said, this is in response to the Vegas shooting in 2017 where the guy was holed up in his room for days, stockpiling weapons.
Other hotel chains have also responded in kind - Hilton and even Disney at the WDW resorts in Florida.
As
platbrownguy notes, this is a property-based decision, not a company-wide one. My most frequently visited hotel is a Hilton that is one of the few actually managed by Hilton. During my 3 to 4 night stays there, I put up the "Do Not Disturb" and leave it up the entire time. I'm not ever bothered.
Granted, I ask the Front Desk if this is okay when I check-in and I'm a repeated guest (20ish nights there each year). So, I may be getting special treatment. But, my educated guess is that the hotel isn't interested in entering the world of security theatre.
But, you are correct that the Walt Disney World Resorts have this dumb policy.