Is Fly Hell anything like 1000 casts for one fish Steelhead Hell?

I'm no purist, I just want to catch fish. I did notice the anglers I watched were anchored and just let their line sit out there. Which kinda confused me - guess I've always thought in terms of moving the fly/nymph/streamer along. Even with dry fly fishing there's movement. The fly is cast and "lands", a fish sees it land and comes to eat it. But these guys cast out and just let whatever it was sit there. So that's what is getting me confused...