It’s the coaching staff. Orr has no idea what he’s doing and Harbaugh is a glorified cardboard cutout. If the DC is stupid (like Greg Mattison, Dean Pees, and Zach Orr) then they’ll get beat by the same exact play all year long because Harbaugh is too dense and stubborn to figure anything out. He’s the same way on offense too. 2 weeks ago vs Buffalo they basically sat in prevent defense all 4th quarter. Last year they regularly played 8-15 yards off the receivers and led the league in blown coverages by a wide margin with the same core group that a year prior under Mike Macdonald finished #1 in yards allowed, points allowed, sacks, and takeaways. Now everyone is out of position on every play no matter who they play while the secondary plays so far off that they can’t make any plays even if they were in the right spots.