Rear Main Seal orientation

Pulled the crank out today, so that I could get at and remove the main seal from the block . Not sure I should be happy with what I found on the rod bearings.

Expert advice required.. PLease !! Not sure what would have caused this... bearings affected are from throughout the block, worst at the back of the engine..

I did have some pieces of plastic that had broken off the bottom of a distributor a couple years ago( which I did not realize) , which I found in the upper part of the oil pump pickup.

probably a dumb question, but replacement required ?? Top halves do not show this type of wear and the crankshaft main bearings look fine, as well as the crankshaft surfaces.

Causes???