I have no probem with erring on the side of over-protecting QBs - the more protected starting QBs are and the less crappy backup QBs I have to see see, the better the product is (and selfishly want Josh protected to maximum possible)
I think the rules are fine today - and think the whole "it's not fair to the defense" when a QB is ambling in the open field and going to slide because the D "has to make a 1/2 second decision" is total BS. In the case of Lawrence, Al-Shaair had penty of time to see that Lawrence was going down. Even if you've left your feet, just don't forearm shiver the guy in the face. When a QB is going down the D just can't try to lay a hit on them. In the case of Mahomes on the sideline - just get your arms around him - don't try to make a big hit (or be paralyzed bc you're afraid a big hit will draw a penalty)