That's nothing to be ashamed of, it's a superb album. And Karn Evil 9 is still one of my top top prog performances.
I think the song is about a futuristic circus, that's certainly what the actual music sounds like.
As for Big Generator, yeah it's terrible, but I wouldn't call it worse than Love Beach, if only because I think Final Eyes is actually a pretty good song. The only redeeming factor in Love Beach is that it's hilarious.