Is that really the artists or the programmers? Graphical bugs are generally an issue with coding and not an art issue. In fact, just about all bugs originate in the coding as that is what the world is built on.
The problem is, their priorities don't seem to mesh with what players are constantly asking for. I mean, they have their artists work on improving shadows and lighting, something that I never really heard many requests for, and yet those same artists can't seem to fix a lot of the graphical bugs currently plaguing the game.