Some bias' are better than others. In this example, a bias to avoid sunk costs is judged better than a bias to accept / seek out sunk costs. Just as I judge a bias to be or seek the awesome is better than a bias to accept or seek tedium. If "bias" is equated to "disapproved" only, then all sorts of positive outcomes can go unrealized. A bias toward rationality, toward finding people who can offer strong arguments against my arguments, a bias towards beauty, all are delightful bias'.