Knuckles rusting?!?

Ok, they are made of metal, they will rust. But flaking off in chunks and being able to pick it off with a screw driver? I was replacing a wheel bearing the other day and was amazed to see my knuckle rotting away like that. Maybe even alarmed... :dunno:

Particulars: Running ceramic pads, no dust shields, jeeps not rusty (except the one rocker I mashed flat 5 years ago), live in Southwestern Virginia and mostly interstate driving anymore.