dadpad, It's more complicated then that. It has started major debate starting with exactly what you are saying.
Remember everything Ive posted here are from "graffiti artist". Please endulge me and take a look at the link to wikipedia on graffiti art.
Right here
"Clean Train Movement" Era
Currently, the graffiti movement is in the "Clean Train Movement" (1989-present), and is characterized by a majority of graffiti artists moving from illegal graffiti to "street galleries". The Clean Train Movement started in May, 1989, when New York attempted to remove all of the subway cars found with graffiti on them out of the transit system. Because of this, many writers had to resort to new ways to express themselves. A lot of controversy arose among the streets debating whether graffiti should be considered an actual form of art. [4]
During this period many graffiti artists have taken to a new medium, displaying their works in galleries and owning their own studios. This phenomenon had started in the early 1980's for artists such as Jean-Michel Basquiat, who started out tagging locations with his signature SAMO (Same Old ****), and Keith Haring, who was also able to take his art into studio spaces.