The glancing blows are shredding 1 handed weapons for S&B tanking. They don't have the double durability of 2 handed weapons to survive the extra durability damage that comes with glancing blows.
This is extra impacted by low damage per hit higher doublestrike 1 handed weapons like daggers for VKF bears. In addition, since tanks like bears are rolled for reaper where you swing 2-5x as much and die often, the extra swings compounds on top of death durability loss, and the weapons literally crumble in your hands.