First of all, they put up 30 points 4 times this season (counting a game w/ 29). They are still 19th in points scored. Even taking out the Siemien start, they still only average 21.67 with Fields. So, yeah, not anywhere close to 30ppg.
Secondly, do you think it's sustainable to put up 30 points per game when you can't execute a simple dropback pass because there is pressure in the QB's face in 2.5 seconds or because WRs aren't getting open? Sure they held up vs GB this week, but just the week before they allowed 5 pressures on 8 drop backs with Trevor Siemien getting rid of the ball in 2.3 seconds.
Third, we've seen Tua, Hurts, Allen, etc. take off when their teams added a stud WR. We've seen stud OLs make guys like Jimmy G and Jacoby Brissett look like solid QBs. I know they aren't getting both a stud WR and stud OL, but they need talent there. And a lot of it. I didn't say you said to spend all capital on D. But you are suggesting to spend ALL 4 of the only top 60 picks Poles has (last year and this coming year) on defense.
Support your QB for once.
Draft after Fields- Brisker, Gordon. Now you want DT and DE first 2 picks, granted did get Jenkins in 2nd
Draft after Trubisky- Roquan, granted did get Daniels and Miller in 2nd, then didn't have another pick til 3rd
Draft after Cutler- granted no 1sts or 2nds but Gilbert, Wootton, Major Wright, McClellin and Kyle Fuller were some of their early picks after having Jay.