While I think the IG setting suggested earlier may mute some of this, the annoying thing about virtually every EA game to-date is that if you stack your defense, CPU QBs can get all conservative like you described. It's a very tricky balance...one I've only been able to truly crack on one game (my current NCAA14 set)...and those sliders are different than M16s.
Try turning IG back "on" in the main menu as suggested earlier and see if it cleans it up. I loved the effect it had on the run game, but if it has a deleterious effect on how the CPU passing game works, that is problematic.