It's just bad luck, It's not some nefarious plot.
Buffalo runs what 80-90 offensive snaps a game based on your style of game planning that's 80-90 injury rolls per game for your offensive players.
Plus your QB passes way more then anyone else...it's not even close and he gets sacked way more then most based on volumn. I'm pretty convinced QBs only roll for injuries when sacked which is the reason most QBs don't get hurt...they have fewer injury rolls.
As much as you want to control everything and think the Sim is rigged to punish success....it's just luck one way or the other in the end.
The only thing in your control when it comes to injuries is your fatigue settings. The more plays a player sees...the more injury rolls he must survive and when a player is targeted more..he has a higher probability of getting hurt.
Injuries **** but it's bad luck...nothing more