What kind of place is Baltimore if their "openness" doesn't allow horse/tree connectivity? I realize it's probably IP/patent related, but geez folks, can't we work this out?
Probable actual reason: A horse tied to a tree will gnaw on the bark. If they gnaw away a ring around the trunk, the tree will die. If it is your tree, on your own property, fine. But if it is my tree, and I have not given you permission, or it is a tree on public property, it is perfectly reasonable for it to be illegal for you to tie your horse to it.
The other laws seem reasonable too. What if you neighbor starts collecting goods and holding a garage sale everyday? When does it become a commercial enterprise in a residential area? I am not sure I would draw the line a twice a year, but if zoning means anything, they have to draw a line somewhere.
Fruit on a wharf attracts fruit eating insects, which can spread to/from ships, encouraging the transfer of invasive species. It is a reasonable law.