Jeff,
You have a good point and the truth is I try to speak to all sides of the issue. Howeever I do stick in most cases to the aesthetic value of tags or full blown mural productions. I am fully aware that unwaranted graffiti happens and that people choose to respond to it in different ways. As a graffiti artist that spans decades in the artform and has traveled a large part of the US and major cities that have graffiti backgrounds. I have seen folks that take tagging to an extreme and fight the anti-graffiti agenda with harsher tools like glass etch, tar paint, fire extinguishers, and the likes. I have never agreed with this sort of work, but do understand that eye for an eye mentality behind it. I tend not to defend nor denounce those folks because they are the proverbial bad seeds if you will. I would also agree that these are the folks that cause most people to have a prejuduce towards all forms of graffiti. At a certian point in time the term aerosol artist was utilized to allow some folks to steer away from the traditional stigma attached to graffiti. I never went that route and choose to just call a spade a spade and in my time I have done my fair share of the stuff people don't appreciate. However in my own time and without police interaction/jail time I found my way into the art side and find my peace there.
Truly what it comes down to is FAME! Most graffiti taggers are ego driven/look at me know types as opposed to the graffiti artists who utilize talent to gain FAME. When someone tags a block 20 times most people will notice their name, but when someone uses a fire extinguisher to tag the entire side of a building in 5 seconds well that hit is going to catch every eye that passes and thus more fame. Again I do not agree with this method and would rather spend a weekend creating a full color mural for all to enjoy and would in the end get more fame and exposure from the quality of work and the general acceptability of murals over tags. I however am not every graffiti artist or fame junkie on the street. The guys that have been creating most of the very negative slant on graffiti (i.e-PBJ, HWC, ect.) are strictly fame junkies and get a rise out of the number and size that they can paint as much as they can. So far they have avoided the police even though they are very much in the public eye and never steer far fron using the internet as a venue to acquire more fame and essentially poke in the face of the local police. I have a mutual respect for these guys, but also would never subscribe to their means of getting fame or enlarging their ego's.
So I do not think that anything that comes out of a spray can or fire extinguisher is art and/or justified. Most of my arguments are based on aesthetic value and the fact that graffiti is and always will be recognized as an artform. I will never subscribe to the thought that graffiti is only art if permission is given and know that anyone that makes such a statement is far from an artist, art patron, or art critic.