Sorry but been in the hotel business for 20 years and you hear claims like this and so many times, it is NOT the housekeeper. It is not worth their job, management can track door entry and many times in Disney and other "better" hotels, the housekeepers want to keep their jobs. Turnover is not as high as you expect and they won't risk it for that.
There are pros that work hotels (yes, this includes Disney), where they might grab a door before it closes all the way, lift a room key, grab access during cleaning etc. It is why guests should use not only the in room safe but safety deposit boxes for the big ticket stuff.
And staying on topic, you would not believe the horror stories my housekeeping staff has had to put up with some guests. And these are 4 star resorts I have been Room Manager in. Everything from guests pleasuring themselves on purpose (to be caught), to guests filing false claims to spreading human feces on the carpet.
Sorry but on my side of the fence, the problem can be the guests in many cases.
