I never said it -wasn't- art.
However the difference between IT and MY art, is the fact that I don't have to run from cops to do mine.
I'm not against the aesthetic of it. There's a lot of interesting and exciting work out there, and yes, I've seen some skilled stuff; I travel. To some degree I also have respect for someone who can master the intricacies of using and controlling a spray can, and someone who can work quickly yet skillfully.
But I don't respect the act of victimizing someone else's property or other public spaces where the work isn't commissioned. In civilized western society we're allowed to draw and paint whatever we want on things we own, regardless of subject matter, so there's no need to mark up other people's stuff. Perhaps one day when I live in a place where freedom of expression is being irresponsibly hindered I'll feel differently but that's not the case right now.
Now, what strikes me as naive is the idea that art is ONLY valid when it's made under the stringent criteria of being made for "free" and "for expression\". The way you've defined "purity", whether or not you realize it, is implying that there's something "unpure" about being paid to draw, and the implication of anything with regard to purity further implies that one is "right" and one is "wrong". A sizable percentage of notable historic artwork is commissioned work. Its influence on culture is heavy, but people paid for it to be made to spec. Additionally I'm sure a ton of professionals and aspiring professionals would beg to differ about this sense of art and purity that you haven't really been clear on in the first place.
What, by your definition is "pure", and if a work of art is "pure" by your definition, does this mean that "pure" artwork is better or more important than "unpure" artwork? How? What's even the point of designating between the two?
Then you go so far as to say that graffiti is this form of "pure" art when you yourself acknowledge that a function of this type of work DOES lie in marking territory. That fact alone makes it as impure as other avenues of art would be. Some is good, some is not, just as you said, and thus, graffiti isn't any type of "pure" art.
Sorry I didn't expand on this but the sparkly rainbow farts comment is really my own observation of people who post about graffiti on Gaia. There's always a guy who comes in this forum, posts about Graffiti and is just dying to mention that it, too, is valid art as if the rest of us had never realized this before. Also, the people who post about it (in my experience) always tend to over-romanticize it as if a graffiti artist is somehow more noble than some boring jerk who just paints on canvas. You're another guy in a long line of guys who do this. I tend to categorize idealized notions of art under "sparkles, rainbows, and other sickeningly sweet crap", and should have clarified a little more.