Why do little kids like Soulja Boy instead of lets say..... Nas? Lupe Fiasco?

because that's what they are growing up on... They are hearing these songs played EVERY DAY (at least 2 times/hour where I'm at)... They dont have much of a choice.... Plus their friends are all doing the same thing and they want to follow the crowd... As they get older they will have more of an "ear" for music.