Matt Bonner puts up about as much resistance as a cardboard cutout of Matt Bonner. You are correct that he keeps his hands up, but that's it. He's rarely in the right position, he leaves his man to try to "help" all the time which usually leads to easy buckets for who he should be guarding because he doesn't have the footspeed to recover, and he's terrible at boxing out. Even when he tries, guys usually just leap over him for the board or knock it away from him.
Standing in the paint and putting your hands straight up in the air ≠ defense.