bolognium, hey, interesting thread and I'm kind of glad you brought this up. I'll try to keep it short and say that I do appreciate graffiti art BUT only if it's at least tasteful, or represent some actual talent.
I like the picture that you posted, it's decent art.
My BIG problem with graffiti is this. Where I live I've been seeing a lot of graffiti and it's more of the 'tagging' type. Some punk or punks is going around and just tagging EVERYTHING with the words 'THC' or 'PURE'. It's on front facades of newly stucco'd buildings, building walls reachable only by climbing the building next to it, on every damned light post I can see down a few main roads and pretty much on every sign I see.
This type of graffiti to me is garbage, nuisance graffiti. It has no artistic merit and looks like garbage, making the surrounding area look like garbage, it drives me up a wall I wish so much their little fingers will freeze off this winter.
On the other hand I think that a well done artistic urban graffiti mural is really cool and can really add something to an existing space.