When RW fired TD and hired Marv, it set in motion a chain of events that have made this organization NFL Siberia. After ML retired, Brandon was inexplicably promoted despite having zero NFL personnel experience. When he realized he couldn't handle the gig, Nix was promoted. This after DJ had been fired and the organization conducted all of 2 interviews (Guy was the other) for the GM job. Guy was fired in late January 2010, so the Bills really had one option all along. Did they interview guys like Eric DeCosta from Baltimore or other personnel directors? No. And I chalk that up to RW being unwilling to commit to someone he didn't know. And so he went with Nix, who despite having the owner's favor, presides over a team 10-23 since his hiring.
No one wants to work for this team. It's why the Bills didn't conduct a real search for a GM in late 2009. It's why they ended up with Gailey as a HC after 5 coaches (Leslie Frazier, Jim Harbaugh, Russ Grimm, Brian Schottenheimer, and Ron Rivera) turned this team down. That's not a coincidence.
Moral of the story? Repeated bad executive and personnel moves make your reputation such that no one wants to work for you. And when you hire inferior talent evaluators and coaches, you get Buffalo Bills football 2001-present. It doesn't help that the owner is elderly, can't guarantee the team will remain in Buffalo, and hires typically only people he knows as insurance against another TD situation.