Let me put it to you this way.
In a world with no cap, do you think these players would be purged? Not just talking Saints here, but around the league, on a yearly basis.
NFL turnover on average is something like 37% per team on a yearly basis. To me that's crazy and cap driven. Wipe out a third of the roster when they get tenure, pay 8-10 rookies league minimum, pay 3 or 4 players 50% of your cap.
Often times you're purging veterans knowing full well you are replacing them with players who aren't as good, which is what I mean when I say a large percentage of moves are cap driven and not field driven. You hope to get lucky with some kids and get reasonably close production out of them at a fraction of the cost.
The solid veteran backup is a dinosaur. Shit, the solid veteran starter is a guy looking over his shoulder now.
EDIT - forgot to mention that the cap went up $10M this year I believe. The problem is you know where that money is going. QB's, LT's, & pass rushers. I think this basic economic structure in the NFL has outlived its usefulness. I'm not an economist, I don't have the answer. But this is broken and has been for some time.