Derek Carr - Why People Dislike Him (IMO)

Rouxble said
In short, Manning continued to produce without Caldwell, but Caldwell couldn't continue to produce without Manning.

The short comings of his head coaching gig in Detroit always seem to overshadow the development of Matt Stafford at that same time.
Unless we ignore him going from this:

to this:

Him not being the best head coach doesn't negate what he is good at.
This also shows how standards are set differently for "reasons," but that's another topic for another day.

Rouxble said
I think it's more about the narrative that these coaches can just take anybody at any time and put up the same numbers--the QB matters. Purdy has made a lot of people forget how Shanahan did with Hoyer, Beathard, and Mullens (and I suppose Lance). Shanahan is 62-49 overall in the regular season, but it you break it out by QB, he is 9-29 without Purdy/Jimmy G and 53-20 with those QB's. It's a huge difference in performance based on who is taking snaps.

I wouldn't say that coaching is irrelevant, but I still stick to my idea that OL > QB > OC. Bad OL? QB will be severely limited. Bad QB? Coaching can only do so much, but the great QB's will be able to function in just about any system unless we're talking about having Peyton Manning run the read option.

I didn't say the QB didn't matter. My argument has been building the scheme around the QB. Crap, everyone talks about Purdy ignoring that he is basically Jimmy G with a "stronger" arm. Look at both of them operating Shanny's system and the only difference that really sticks out is Purdy is actually willing the throw the ball further downfield (Jimmy G wasn't about that life..lol).

I agree with you to a point but we've seen too many QBs leave bad coaching/scheming/team/bad fit and become more successful. All of the things you listed are needed for success. But this goes back to the point I've always said. A great coach can make an "average" QB great. A bad coach can make a "great" QB bad.