I'm going to sum it up in a few words: kids have gotten lazy. I don't think anybody wants to take the time to appreciate more complex music, and more importantly, nobody wants to put in the time to learn how to play more complex music. Obviously there are exceptions... us folks for one (assuming that you grew up in the eighties and ninties). Grunge paved the way for lack of real musical talent, and its perpetuated itself to the point where whats popular is simple repetitive beats with brainless, shallow lyrics.
Obviously there are exceptions.