Same reason it took McBean forever to finally give up on Peterman, they drafted him and are giving him every opportunity to succeed.
Sometimes the player isn't the better player, it's an ego thing for coaches and GMs.
Do the Bills become a worse team by ridding themselves of Foster or Jones?
No
Are the Bills a better team when Foster or Jones are on the field?
No
Would the Bills be a worse team with Williams on the the active roster?
No
Would the Bills be a better team with Williams on the field?
That's the unknown, a worse team, No, a better team is a real possibility.
That said it only seems like a win win and a no brainer by getting rid of one or both Jones/Foster and promoting Williams. IMO it is just a matter of time, maybe Beane is holding out hope of a trade or something.
Miami stinks. Hate all their players, coaches, front office, fans, hate em all!
After 4 SB losses and 17 years of futility I don't feel sorry for anybody/team that loses on purpose or otherwise.
Eff em all, GO BILLS!