Apples and oranges.
No, you do not have the right to leave your car ON A PUBLIC STREET for weeks on end.
Graffit on YOUR PRIVATE PROPERTY is just that. It's your private property.
Find a different analogy.
We have recently implicitly qualified a public good from the perspective of a public view; if you build to block a view you can be made to tear down the obstruction.
This way, the state controls all they survey and ugly scenes must be made pleasant.
We must eliminate blight.