A lot of Bresees issues in the run game is due to his hips and pad level. They're just wayyyyy too high. It's also worth noting he's not just a poor run defender... he's legitimately one of the worst iDL against the run in the entire league.
The "he's a good pass rusher" thing is so ridiculously overblown. Most of his sacks came off coverage and stunts. He's not beating his guard one on one consistently. In fact his pass rush win rate is a very pedestrian 8% (lower than his rookie year).