I think the turnaround must point to the coaching staff changing the game planning from what they may have wanted to exploit as their own system to one that recognizes the strengths and weaknesses of every guy who takes the field and uses that to their advantage. I don't know specifically who gets the credit for that, but it appears to be working.
For me the turning point was the Bucs game last year. First time I saw a complete game. Lots of backups, but Zack had a really good game, and took the reigning champs to the wire. Our great draft (and our 6-3 record this season!) is icing on the cake. But the Bucs game is when it clicked in my brain. I could actually see a path forward for the first time.
The turning point was when ZW came back and the Jets offense stopped revolving around the passing game. First 3 games: 164 drop backs or 54.67 a game. Last 6 games: 179 drop backs or 29.83 a game. Sometimes it takes a truly bad QB to focus the CS on what is important. Flacco was bad but not truly bad.