Madden's CPU roster management logic is the product of a few things:
- scheme-specific OVR ratings are designed to give teams personality. For example, they prevent a 3-4 team from frequently trying to sign Cover 2 OLBs; they will go after pass rushing OLBs which actually fit what their defense wants to do. If a player on the roster doesn't fit the scheme, he's going to have a low OVR and the CPU is going to cut him. Without scheme-specific OVR, we end up in a Madden 12 situation where teams are signing players that don't fit their defense and aren't helping them win.
- the CPU roster management takes old age into account and is biased against it - so you'll see veterans like Jared Allen get cut if there's a similarly-rated and younger backup.
- the CPU roster manager appears to have no explicit bias
for youth or invested resources. This is the Phillip Dorsett example; the game doesn't care that he's like 22 and a 1st-round draft pick, it just sees him as a young player who's a poor fit for the scheme, so the game cuts him.
- I'm not 100% positive on this, but I believe the CPU does favor developing rookies and young players if Game Prep is simulated (should the CPU decide to use the XP activities). So there is some capacity for the CPU to "develop young players".
- The CPU's roster management is very "win today" oriented at the expense of tomorrow. If a rookie isn't good enough to immediately contribute (by OVR rating), he's at risk of getting cut, regardless if he has a high development trait or elite physical tools.
- The CPU immediately considers factors that the user doesn't normally consider in roster management. Notably, the Size and Durability ratings influence the scheme-specific OVR rating. This is another reason why the Colts almost always cut Phillip Dorsett; he's small in stature (5'10" - 180 lbs) and his INJ / TGH ratings are very low compared to other receivers on the Colts roster.
I do think that the CPU's roster management AI could stand to be more robust. I do not think that what is currently there is ill-conceived.