While I agree that adequate isn't enough long term for midfield and defence, it certainly trumps our attack right now, which is entirely inadequate. This isn't about accepting the current standard as the end goal, this is merely about the order of priorities.
You can't make a silk purse out of a sow's ear. No matter how effective the midfield and defence is in both directions, I don't see remotely enough quality in our attack for our manager to get the goals out of this team he needs to survive another season. Both in terms of results, but also in terms of giving the fans something to have faith in. Another low scoring season with little to cheer in front of goal will have the fans turning, even if we start to have better possession and positional play. There's already a perception that the manager is defensive due to the need to play two full backs at wing back, which is rather unfair. But prioritising improving our defensive and midfield base at the expense of our attack would test many fans' patience.
Besides, I disagree with your assessment about why we struggle to play out of the back. My view is that it's incredibly difficult to play out from the back when your front players fail to stretch play, fail to make effective runs into space, fail to hold the ball up, and fail to win their duels. We're routinely leaving our defenders and midfielders 1 or 2 bad passing options instead of 3 or 4 good ones.
I don't think any defence or midfield can be so good that they can maintain territorial dominance with an attack that will routinely lose the ball in 1 to 3 passes, and lacks the legs to press high and get it back. So even if we had the absolute best CBs and centre mids in the world, I don't think we gain much more than incremental gains in terms of end result. Our underlying game might improve, but our end product, not so much.