A clever marketeer, but not really too artistic.

As for graffitti, many of the writers are pretty advanced artists. Street art informs the creative industries and many within those industries would probably admit it's influence is widespread. It's a genuine urban art form, created on the streets by people who are not part or have an interest in any commercial or establishment body.

A few writers go on to exhibit commercially, work in the graphics industry. Many have a very highly developed understanding of letterforms and form in general - often more so than many graphic designers these days.