Our decks are not strewn with soggy sail bags and salon cushions. We pick up trash we find floating in the marina. We look after the boats around us and we are good neighbors in many other ways. If it's really the derelicts you want to get rid of, then do so. Don't lump all of the live-aboards into that category though or you'll be as guilty of discrimination as any racist.
Selective enforcement is already common practice.
Make your rules fit the problem and don't look down your nose at those of us who have found a better way.