Stuart, I wouldn't disagree with you, but just to throw my personal opinion out there next to yours -- I actually see some good value in RC simulators for basic training and practice. I think (although I'm not really a heli-pilot) especially for helicopters -- the cost of crossing your thumbs the wrong way with an expensive heli can be $100's or maybe even $1000's -- and the sim can give you a lot of practice time before you go out and do it for real.
I always have trouble with lining up the landing or just getting completely out of position because you don't have the peripheral vision or sense of where you are at relative to the field when you see everything through a 20" display. That said, lining up a good landing in real life RC flying can take a couple tries too.