Come on Fred, it's not all that complicated. What we are talking about is a bunch of over age kids scribbling on other peoples property.
It's natural for children to do it because it's apart of mental development. When young men reach the age of reason their perspective should of advanced far beyond simply making people upset. I think this arrested development is mostly due to these young men not having the adult direction you provided your kids.
What ever happened to us as a culture where using trash mouth in songs thatdisrespect woman and slopping paint on someone elses property is confused with art.
I live in Philadelphia and our city is full a beautiful wall art that I think is wonderful. But those people who did that work are trained artist who spent years developing their craft before showing it off.
Come on there is nothing deep about this, just a bunch of out of control narcissist trying to impress other juveniles with their daring.
Also, I would venture to guess that most people know exactly why they feel the way they do, we are not a bunch of children. They just don't wont to waste their time talking to us about it.
Our big problem as a people is that we no longer have clear lines of right and wrong. Maybe we over think everything, we tend to feel, not think.
The whole thing is very basic to peoples mental state of growth. Like I said above this is nothing new or complicated, it's been going on for mellennia. Society must have rules or there is no structure, no structure and we as a people drift apart thus slipping into the status of a foot note in history just like the Romans.
That is one big reason why most people hate graffiti, we see it as an assult on our value system. To us it's not art, it is vandalism and little more.