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?