Simply, it would be more beneficial spraying paint into a bag and getting high off the fumes than using it for the incoherent, illegible, worthless tagging that is scrawled upon buildings, schools, buses and trains everywhere.
I really want to see awesome "gansta" names on the side of shopping centres. It really adds class to the place. You fucking idiots.
Tagging is not art. I will personally punch anyone who claims this repeatedly in the face. It is vandalism, and nothing else. Graffiti can however be art... if it's done appropriately, legally, in the right context and in the right place. There is a big difference between a social statement and someone's name on a park bench.
Anyone caught tagging should have "wanker" or a word to similar effect etched onto their foreheads. Would seem appropriate, wouldn't it?