As for protecting people doing things illegal/immoral/shady, too bad for them. They shouldn't be leading double lives or whatever, and if it wasn't a forgotten item at a hotel that tripped them up it would be something else equally silly. I hate the fact that 99% of us have to be inconvenienced to protect the 1% of people doing stuff they're not supposed to be doing anyway.
But what really burns me up is when I do call a hotel where I know I've left an item and I get the lost-and-found runaround like a previous poster said. I've never left anything irreplaceable or hugely valuable (thank goodness), but just stuff like a book I was in the middle of or a set of pajamas. I can't imagine housekeepers stealing that kind of stuff, so they must just be throwing it away, then counting on the piss-poor lost-and-found process to discourage guests from pursuing it too far.