I know of a couple fancy harbor houses in Newport Beach with big docks / slips which often don't have any boats in them, or at most have a Duffy there. I've heard 2nd hand that they prefer a clear view to the $$$$$$ they could surely rent out the slip for.Put yourself in the place of the watcher. If you're looking out across the water, boats are part of the expected and, especially in the case of sailboats, desired scenery. If you're looking out your front window across the street and see someone else's motorhome, its just interfering with your view.
On the other hand I've seen huge powerboats that are bigger than the houses they're docked in front of.