It's because the tendencies sliders affect the ovr. rating for some reason. And pitchers have a glitch where their walk tendency skyrockets, causing a drop in ovr. rating. Causes a ton of walks.
The hitters have the same sort of issue with the stealing tendency. It actually raises the player's ovr. This results in everybody stealing at least 25 bases.
Progression is flat out broken, and 2k was made aware of this before the patch. Neither issue was fixed, and they actually said they fixed the steal rating.