Why? Because Edwards was Chan's pick for the DC position and he is not going to give up on him after one year (no matter how crappy the D was this year). If you give up on him after one year, what does that say to the new guy if his new scheme doesn't work next year? Also, your players are forever in a state of learning a new scheme and will never fully grasp it if they are changing DC's year in and year out. Are there better options out there? Without a doubt, however those other options will have a high cost and Wilson will not pay a DC as much or more than he is paying his head coach. We're stuck with Edwards for at least one more year, if there is no improvement next year (not sure how there can't be), then I would expect a change.