Whether people like it or not, factors outside of artists' music DO affect who or what we listen to. An artist's persona and character is part of their overall appeal, and it's also represented in their lyrics.
For example, Nas. I've always thought that one of the reasons why he has this huge fanbase on the internet is not entirely due to the quality of his music. Nas has the appeal of an "intelligent thug". His lyrics are deep and introspective, and some might even say nerdy at times, but he also has another side to his music. He's from the hard streets of NY, lived in the QB projects, grew up poor, etc. And he also had the whole mafioso thing going on. So you see, he's not as, you know, his lyrics aren't as "dumbed down" or "party oriented" as say, a 50 Cent, but he's also not as nerdy as an Aesop Rock. SO i think kids on the internet like listening to Nas because his character and appeal makes them feel better about their listening experience. They like saying "I like Nas" because they can't be accused of, i guess, following the masses, but they don't feel like they're too geeky because Nas has a thug side too.
Also, i know that everyone isn't like this, and my observation may be completely wrong, so don't get offended or whatever.
I don't even know if i'm making sense.. can ya'll see where i'm coming from?
Another example could be Jigga. I mean, his whole lifestyle adds to his appeal. Who wouldn't wanna be him? He's a young, black male who grew up poor and is now the most well-known rapper in the world, is one of the richest men in America, has "the hottest chick in the game, wearin his chain", etc. He's cocky, confident and living a great life and this shows in his lyrics and his flow .