Just because something is illegal, does not make it immoral or unethical by itself.
I do understand the argument against graffiti, but there’s also something to be said about any kind of expression that’s inherently rebellious and counter-culture.
> Would you be happy to wake up and see your car covered in paint? What about the windows on your house? Would you see this as an "improvement" too?
Correct me if I’m wrong but the vast majority of graffiti is on public walls and facades, and not on houses or cars. At least here in the Netherlands that’s what I’ve seen.