RBK strength and PBK strength should really be less about strength and more of a skill in my opinion.
For example a player's ability to push a defender back and open up a hole is dependent on a few abilities. It requires the strength represented by the strength rating but also requires the leverage and positioning and technique to get the leverage advantage and push the defender back which should be shown by the RBK strength.
Keeping from being shoved back into the QB in protection requires strength to match the opponent and fight them off but also requires the technique to get leverage which should come from the PBK strength rating to modify that strength rating.
Without these ratings then any DLineman with 95 strength would be able to become a good OLineman. Also, you may say that the footwork ratings should handle this or are otherwise useless but this is not so much the case. PBK footwork should determine the ability to stay in front of a rusher and move laterally adjusting to changes in direction and some pass rush moves. RBK footwork should determine how well a player avoids being beat by power moves and seals off the hole turning the defender away from the running lane.
As to the "punters being able to play oline" thing that is due partially to the low end limit on ratings still being like 60 even though ratings are now shown lower than that as well as sliders and difficulty levels playing more into success rates than ratings.