I think you nailed it; there's relativism at play. Classical music was the vibrant, popular music of its day. It was the showiest kind society had. As that goal

I think you nailed it; there's relativism at play. Classical music was the vibrant, popular music of its day. It was the showiest kind society had. As that goalpost has moved, classical has become - comparatively - austere. Over the 20th century, but especially the past decade, more and more immediately-satisfying media has come to pull attention (and change tastes) away from the now-slow-burning classical. It's become the vegetables of the music world.