>Because he's supposedly an "artist"
Likely due to the fact that he is an artist in that he makes the bulk of his money from creative efforts. You may not like those creative efforts, I really don't care, but they are creative efforts of some stripe which people pay him to perform.
>some may even stretch and call him a "musician" of sorts?
Yep, because he makes music.
>It is implied that an artist is extremely passionate about the content of their art. An actual artist would not make choices that so directly contradict the content of their art.
Haha, what? First off, the concept of an "actual artist" is cultural elitist rubbish. There's no world of the forms where some platonic ideal of artist is suspended, perfect and timeless, to compare all lesser artists to. Even if there were (there isn't), you certainly aren't magically imbued with the ability to access that world of the forms.
Secondly, artists are constantly plagued by contradiction. Pablo Picasso identified as a communist and was one of the wealthiest painters to ever have lived and that's not a Van Gogh type thing where he was only worth a lot after his death, Picasso was rich as shit during his life. Does that mean Picasso wasn't passionate about economic oppression and was rendered incapable of successfully rendering that message in his art? Absolutely not. Just like a heroin addict is completely capable of saying "Heroin is bad for you" with conviction and weight.
I think you're speaking above your knowledge. Which is ironic because you end your post with condescension.