Well, to answer the initial question of why it is not seen as much, is because classical music evolved in to other forms of music, and that was the new fad, and then that music evolved into Jazz and Blues, and then jazz and blues evolved into rock and pop, and then that rock and pop evolved into what we have today. As the music evolves into something different, so do the people, because they grow up all their lives listening to what their parents listen to until one day they find something different. The rebel by listening to the new music of the time.
I listen to jazz, but not so much classical. I think the reason for me at least to not listen to classical is because I study it in school, and it is kind of predictable when I hear it. I still like it, I just don't listen to it as much.