Well this explains a lot.
They’ve acknowledged it, and are correcting it way beyond just hiring a new coordinator.
Source- The New England Patriots announced that Bill O’Brien has been hired as offensive coordinator/quarterbacks coach.

The Patriots finished in the top 10 in offense every year during O’Brien’s time with the Patriots.
“I am looking forward to working with Bill again,” said Patriots head coach Bill Belichick.
“He is an outstanding coach and an asset to our staff.”
O’Brien served as offensive coordinator/quarterbacks coach in 2011, following two seasons as quarterbacks coach (2009-10).
In the words of other Patriots, the offense was worse than numbers could capture.
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Ive never seen anything like it, one source said.
It was disheveled, another source said.
They were always scrambling to get things done.
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Its always been about winning and doing whats best for the team.
I really believe (Belichick) when he says that, one source said.
I just think he really didnt understand how hard it was going to be.
Let’s pause this for a second while I project my own feelings into this.
His fuck up was trusting Matt Patricia and Judge.
Something to just get his feet under him and get him used to game conditions.
The sources The Herald spoke to expanded on that.
The results were disastrous.
Under Patricia and Judge?
Those numbers were cut by roughly half.
Because we hadnt put enough install in, a source said.
And you would see they hadnt really accounted for that yet, one source said.
And theyd say, Well get to that when we get to that.
That bang out of attitude got us in trouble.
Eventually, the staffs approach ran counter to the reason they had pivoted in the first place.
Remember how Mac Jones has publicly stated he’s a guy who likes to ask “Why?”
Who wants to know the whole thought process behind a gameplan, or even a call?
Joe Judge, they later suspected, was in a long process of being phased out.
Jones trust in his position coach was effectively non-existent.
Mac didnt like him, one source said.
And I think that kind of rubbed people the wrong way.
A lot of people were frustrated with (Judge), a third added.
The piece goes on and on like that.
It’s all there.
I’m sure there’ll be a lot of discussion this winter about who talked to The Herald.
And while it’s an interesting question, it doesn’t concern me.
The problem wasn’t Mac Jones.
It wasn’t a lack of talent outside the numbers.
None of those groups are without blame.
But more than any other sport, football begins and ends with coaching.
Now hopefully the 2023 Patriots offense will be lions led by a bigger, older, wiser lion.
It’s no wonder Mac Jones is feeling so good about the future.