I think some folks are confusing the Bills Wall of Fame with THE Hall of Fame in Canton, OH.
To be a member of the Wall of Fame, the HOF numbers are not a requirement. We have the 12th Man and Bob Kalsu on ours, for example. They were put on the Wall not for playing stats but incredible intangibles or contributions to the team. While there are many other examples, the Bears (Brian Piccolo) and the Cardinals (Pat Tillman) also come to mind of teams putting players on the Wall of Fame that didn't have the "stats".