I believe that if I have a briefcase full of confidential documents, it would be logical that I can leave my workplace with them without them suddenly not being trade-secrets anymore. I can bring them to the airport. I can put it on a chair next to me while I eat and if I forget them, they are not suddenly considered open.

To me, the point of this law is that the finder's-keepers attitude is encouraging theft. I think "I found it" is a common alibi for theft. If you get rid of that alibi (which doesn't harm people who would return the items) then you discourage actual theft by making it harder to buy and sell.

The only people who are inconvenienced are those who truly did find an item and keep it. There's an exemption for items of small value so as not to burden those people too much. That's just my view of it.