Boy, I would love to know the ages of the pro- and anti-graffiti camps. I suspect a serious generation gap.
Anyway, one of the most effective proven ways to combat unsightly graffiti and gang tags is to have a city-sponsored mural program. It's a cornerstone of Halifax's, and, I think, most Canadian cities' anti-graffiti efforts.
And we can all agree that some graffiti is more desirable than others, right?
This is terrible vandalism, perpetrated by dumbass teenagers, probably.
Whereas
this or
this are improvements on what would otherwise be blank, ugly walls. And are 100 percent not gang-related, and I doubt they're lowering anyone's property values.