This is an old and IMO inaccurate narrative. We have spent plenty of resources on defense - they just haven't turned out as good as those on offense. Our scouts are much better identifying offensive talent than defensive talent. We had Mo, Jones, Taco and numerous 2nd rounders on defense. Either our scouts just can't find defensive gems or we can't develope them.
I respect your opinion but I do not agree. And here's why:
We drafted Mo and then switched schemes 2 years later, knowing Mo was a press man corner and switched to zone
Also overpaid Carr who again, man corner, and switched schemes 2 years later
Then we turn around and take a 'risk' on Gregory which is very Jerry-like. How'd that turn out?
Got Greg Hardy, how'd that turn out?
Got Escobar when we could have had Fletcher Cox.
I think our drafting issues are pretty well documented and its fair to say the defense has got a crappy end of the stick when compared to the offense. You also hit the nail on the head "numers 2nd rounders on defense." Most of those were either late 2nd rounders or 2nd round "risks" nothing guaranteed.
Meanwhile the offense got Tyron with pick 7/8, Zack Martin with pick 14, La'El Collins who would have went early round 1, Dez Bryant whom would have went top 5/10, travis frederick whom really was a 3rd round grade but the best center in the draftin round 1. The offensive side of the ball got ALL guaranteed players that would contribute right away whereas the defense got "high risk high reward" and "guys with potential." I dont believe its fair to say Byron would have the same immediate impact on defense as Dez would on offense. Same with Randy Gregory to Zack Martin. Or Taco to Tyron etc. Offense pretty much had guys that were going to contribute and have an immediate impact.
The reality is that Jerry is the main problem but he's not going anywhere.
For years people blamed Romo for the Cowboys failures, but people finally realized after last years debacle and will see this year that Garrett is the main culprit (besides Jerry)