I think one reason JB takes so much heat is that the organization whether intentional or just coach speak gave fans the impression he was fully capable of stepping in and being the franchise QB. A lot of fans fully bought into the hype and pushed that narrative as well. Then when it became obvious to many he was not franchise level and his flaws were obvious many posters insisted on continuing to push the narrative that JB is the man. I believe the JB defenders digging their heels in with constant excuses even as more flaws were discovered and proven caused him to take more heat than he he would have taken otherwise.
You seem stuck on a false belief in JB being above average and you don’t seem willing to believe it when others point out that even with all his weapons healthy, JB was not performing well at all. He just isn’t an average QB, he just isn’t. He will never carry a team to wins, he needs lots of help. I will also add that I don’t think his OC has helped him with schemes either. He is still trying to fit him into the Luck Passing scheme. It’s not good for JB though.
As of now I am actually not a Chad supporter (never have been) nor do I think JB has proven to be a franchise QB either but I do think JB is above average. Having said that, our season is clearly over so I would play Chad these last 3 games just to see what he has, It wouldn't hurt a thing and JB can rest his knee and get healthy.