The problem with boats parked in a driveway versus a cat with sails up on the beach is that the driveway version looks like crap. Beach cats and other boats on trailers are about as pretty as parking a semi or broken down,rusty old cars. That's the principle behind those rules. The same with a 30 foot blue tarp that you can see from your back yard. I know it woudn't bother me, but I can see how it could bother someone who paid for a nice view from their yard.

Unfortunately all those things make neighborhoods look shabby, and that ultimately affects the property values.