xash
My posts are directed exactly to the situation you are describing.
The problems I am raising come about when someone lets their foot rest on the pedal alot without actually depressing it.
This just makes the throw out bearing spin all the time and will cause it to fail prematurely.
scotth,
On some vehicles (some Nissans in particular that I know of), the release bearing contacts the pressure plate slightly even when totally disengaged. Hence, it will always be “spinning”.
Your argument, while it makes some sense in theory in practice it does not. It is simply not the most common cause of clutch faliure when “riding” the clutch.
It may not apply to all cars, but it is common enough.
On porsches and bmws and many fords, it does apply.
I have seen two failed release bearings. One was because the seal popped (defect IMHO) and the other was improperly mounted and bent the sleeve.
I have replaced several clutches that were worn before their time (say, oh sub 50,000KMs) and each and every single one the disk was scored but the bearings appeared to be fine.
One of the vehicles I worked on was a Mustang and that driver used the clutch as a dead pedal. The bearing was fine. The disk was not.
However, I doubt that I am going to change your mind so we’ll have to agree to disagree.
So, scotth do bernse and I get to ask what your credentials are? 
P.S. Maybe you need to get a better brand of clutch bearings. The cheap ones (the “throwaway” types, as you say), IMHO, probably don’t last as long. 