Yes, some people use spraypaint to make stunning, socially relevant art. Banksy is, in some sense, a graffiti artist.
But most graffiti has nothing to do with Banksy-esque social commentary. In fact, much of it is simply gang signs labeling areas of turf control. The people writing these gang sign messages are absolutely not interested in having a specific, authorized place in which to exhibit their street artwork.
It's some seriously privileged classist stuff to make the claims that you're making
It's "subjective" whether or not gang tags constitute art, rather than a danger to the community?!?
Huh?!
It's crazy how some people think painted symbols present a danger to humans somehow
I'm trying not to be offensive or personal here, but I'm stunned at this take that refuses to acknowledge how dangerous and harmful street gangs are to communities. If you've ever had to live in a neighborhood with them, like I have, then I doubt this would be as much of an issue for you?
We aren't talking about that sort of painted symbol, though. I'm totally mystified as to why you refuse to acknowledge the nature of gang tags. They aren't art, and aren't intended to be art. Instead, they're enciphered threats to other criminals in the area, warning them to stay out. They don't and aren't intended to outlast the people who painted them.
And most importantly, they represent real danger to the entire community. Turf wars, mistaken identity shootings, as well as gang activities like narcotics, sex trafficking, and robbery/burglary are all to be expected in areas where gangs openly declare ownership of turf with tags.
Also stating again: intent does not matter
Because in some rail yard somewhere lurks some really decked out train cars, you want to prevent a neighborhood plagued with gang violence from protecting their community?
If you really want to stop gang violence, people in poverty need opportunity and investment. Preventing gang members from painting things does nothing to solve the problem of violence, that's an absurd conclusion.
The theory you are presenting, of monocausal criminality due to economic conditions, has been analyzed thoroughly and rejected decisively by the field of criminology for decades, now. It's easy to see why: we can compare impoverished groups both nationally and globally and discover that there is simply no causal, consistent relationship between poverty and violent criminality.
To be sure, economics can play a role and become a factor in motivating criminal behavior, but violent criminality is ultimately a choice that people make, not a direct consequence of poverty. Indeed, many groups suffering tremendous poverty exhibit very low rates of violent crime, and likewise, Suge Knight exists.