This seems to happen with progressive rock at alarming levels. They just reach a point where they take their pretentious bullshit a little too far, and the fans grow weary of it. You saw that with Jethro Tull, which pushed its luck with A Passion Play after scoring a critical success with Thick as a Brick. Yes took it too far with Topographic Oceans. I'm sure ELP has an album where they pushed the envelope a little too far and pushed away the audience in the process. Unfortunately, that had a pendulum effect, with ELP releasing the wimpy Love Beach in an attempt to reel back in those lapsed fans.
I think A Passion Play being my favorite album in that whole genre might be my least popular opinion in all of music, I really don't get the hate. And I'm not really a Tull fan even.
I feel like Topographic Oceans could've been way better if it was condensed by almost half its runtime. The songs have cool ideas, but no focus and they all blend together.