Ali, that quote sems to come from a social critic, but there are many other ways to understand what art is and depending from their starting position they will define art in a way or another. I understand art as meaning and communication, as most of the people here have said, but creativity and skill have their own place here too, we need originality and a high degree of achievement to consider it art and not a simple craft you have learnt and repeat without innovation.
For a creator everything comes from a real necessity to express himself, to communicate with the others, and because he's impelled to do so he starts working, sometimes fighting, in order to be able to take out of his head what he sees (or hears) there with such clarity, the closer he gets to his ideal, the better he considers his product, but then, after it is finished it gets its own life (with the help of the others), sometimes he finds it difficult to accept that most people see a different thing from the one he was intending to create, he finds it a failure, even if they told him it's good, but sometimes this new meaning is also found by the author as in a real conversation with the audience. The fact that art has to stir the audience is more controversial in my opinion, but what art can't do is to leave the audience exactly the same, it needs to move you in some way or other.
When performing sincerity is the most important factor for me, not if they make money or not, I suppose every artist in the world would like to make money, money equals liberty for an artist.
Sincerity is what makes me feel Bono, Egde, Adam and Larry are talking to me in a concert with only 80,000 more people present, what makes me think that they really mean what they are saying, sincerity is also what makes me think they are doing their best possible performance at the moment, sincerity is what prevents them from doing things mechanically every night, even if they play the same set list, that's the magic in the concert, that's why the audience follows them in the trip, the day the lost it they would stop being artists, no matter if they lose money at that moment.