Look at the teams that are IN the division.
Has Arizona actually ever been "good"? Or Great? Consistently? No, they haven't.
Seattle? Come on , seriously? They had a good span with Holgrem and Jerry Jones feeding em picks. Doesn't last.
Frisco is a serious mystery as to why they aren't better. After Salary Cap hell, they had a little success, but, nothing lasting.
And the Rams?
. They are another team that has sucked for decades only to get a little taste of the pie..
I would say it comes down to owners and management. And horrible picks and signings.