Thanks for all the patient answers to my original question! And, it does make sense that more design effort will go into a stabilized lens, but with addition parts and complexities I would still expect it to be much harder to make the stabilized lens.
I'm with Rover, I'll always go with stabilization given a choice. Unfortunately in Canon's wide and normal L class zooms the question is too much money for the F/2.8 zoom, or IS, light weight, and bargain price for the F/4 version. And the F/2.8 by some miracle does not need IS in low light. And by some miracle the F/2.8 is also sharper.
My assumption (I know, I know...) was this was because IS would detract from the sharpness of these lenses. It could also be that stabilizing longer fast lenses is less problematic and more necessary at the same time.
My conclusion, though...it has to cost more to make a precision lens with more parts. But since I don't really understand how it's done I'm not arguing the point. Just guessing. But I think one reason Sony has to go away from IBIS is that they throat of the E mount isn't really big enough to allow adequate sensor shifting. That's why I'm kind of hoping Canon, if it introduces a full frame mirrorless will use a similar sized mount as they use for EF. Then they could actually make a system that is small and doesn't have impossibly expensive lenses. Well, that's my mirrorless fantasy!