SmiZ, I sense a minor flaw in your argument.
Music is often marketed as if it does reflect/represent reality.
We know that Arnold and Bruce Willis are actors, and are not really
like the characters they portray on the big screen, because the
Movie industry sells those stories as fictionally based, and actually
goes out of thier way to tell us otherwise if the TV show or movie
is "Based on a true story".
Books are also sold on a similar model; except for the best sellers,
all the other books are clearly placed in fiction or non-fiction.
And are (for the most part) marketed accordingly.
Popular Music, on the other hand, is marketed in the opposite way.
The promoters want you to believe that the singer actually has some
experience or emotional attachment to the song for you to identify
with. When Arnold says "Hasta La Vista", we assume he's just reading
lines that the scriptwriters wrote down for him; but when a singer
says "I want to shoot so-and-so", we are meant to believe that thought
and desire came from the artist themselves.
Poetry is a little harder to quantify, becuase it seeks to be deliberately
vague on whether it is coming from reality or the poet's imagination.
And most poeple are only exposed to it in the form of commercial jingles
and song lyrics.
Otherwise I would agree with calling it "artistic expression", but isn't
he supposed to be expressing what he really thinks? (Not really,
since Pop music is about selling albums more than selling ideas).
I haven't heard any Eminem songs to my knowledge, but I have enjoyed
listening to some Limp Bizkit singles, so I can see where one persons
offense is another's entertainment.