I believe the Ford 9 inch uses tapered axle bearings. As for Chevys, they use roller bearings with c-clips. Have you ever seen a GM product on the side of the road with a wheel, drum and axle assembly not too far from it? That's because the c-clip broke under an axial (sideways) load. The c-clips are all that hold the axles in under cornering. Heavy equipment, trucks, etc. use tapered bearings almost exclusively. Most have "floating" axles where each axle has two tapered bearings in opposite directions for maximum load carrying, both radial and axial.
Now I agree that Ehrenberg is closed minded and opinionated (among other things,) but he knows his stuff. He also knows a lot of engineers at Chrysler and elsewhere, which is where he gets his info from.
Just because you, I or anyone else has not seen a failure doesn't mean it can't happen. If a failure (especially a catastrophic one) can be avoided why take a chance, even though the solution may not be a convenient one? I think most would agree: I wouldn't want the first failure to be on my car.
Fact: Ball bearings (such as the "green" bearings) cannot take a lot of axial load. Roller bearings cannot take any. Period! Why do you think the front wheel bearings are tapered? Most of the time ball bearings would be OK at the drags or on the street, but if you're gonna do any autocross or road racing a la Green Brick, you need tapered bearings to take the axial loads. I'm not gonna trust the "green" bearings under agressive street driving either.
I wouldn't put "green" bearings or F-body spindles on my car.