Where we have a disconnect re: the Oliver penalty and low "hits" is between how the rule is written and how it's being called.
The rule was written and intended to prevent "forcible contact" on QB's below the knee. It wasn't supposed to be a penalty for tackling a guy low, it was supposed to protect QB's from being "hit" low.
Unfortunately the officials don't want to deal with the subjectivity inherent in the rule so they have just taken to calling any contact at or below the knee as a penalty, even if it is just a guy grabbing hold and wrapping up. If they're not going to call it as it's written, I wish they would just scrap it. They can still leave the stripes the capability to call unnecessary roughness penalties for guys delivering egregious shots to the knee.