Pressure Plate Finger Grooves, caused by the throwout bearing Options

[McMark]

Hey guys, check my logic here. I see this type of grooving all the time, on nearly every pressure plate I see - regardless of engine type, horsepower, etc. I hadn't given it too much thought other than, "I don't like it, but it happens every time." But I was just talking with someone and it occurred to me that this might be wear caused by a bad throwout bearing. If the grease is sticky, or if dirt has infiltrated the bearing, it may not be able to rotate/spin correctly and would slip causing wear.

The point of the throwout bearing should be to stop exactly this type of wear, right?
Doest this mean bad throwout bearings are super common?
Or is this a symptom of a loose clutch cable, not holding the throwout bearing tight to the fingers and that lets them slip?

[Bartlett 914]

A lot of the comments seem to point to the throwout bearing spinning on the fingers. While this would cause wear, it may not be the problem at all. Each time you press on the clutch, the throwout bearing pushes in on the fingers even with the throwout bearing and the pressure plate spinning together (no circumferential slipping). Here the bearing must slide metal on metal without lubrication. This is going to cause wear. Grease would help but who wants grease so near the clutch. Harder bearing and softer fingers means the fingers will wear first.