You're missing the point.
If you keep a Do Not Disturb on constantly, then if anything goes missing, you can complain and they can check the entry log for the lock, and see who entered.
So then the maid or security has to explain why they barged through a DnD sign, and you can press it from there.
If they can now enter when they feel like for "daily checks", if anything goes missing, they can simply deny that they took anything, and their entry will be considered normal.
Usually thieves will go after the low-hanging fruit. They would rather steal when they're "supposed" to be in the room, rather than barge through a DnD and then face a customer complaint when stuff goes missing.