Some coaches are better assistant coaches than they are head coaches.
I don't know about Bates. Certainly he's an excellent defensive coach. He got a little bit of time as the head coach at Miami when Wannstedt was fired, IIRC. Probably not enough time to serve as a reliable barometer.
Ray Rhodes, I think, functions better as a defensive coordinator than as a head coach.
Same goes for Richard Williamson (former Bucs head coach, current Panthers receivers coach, IIRC).
I don't think that Mike Sherman is one of the top ten coaches in the league. That's just my opinion. I'm not sure that Jim Bates would be an improvement, however.
That said, the Packers have a good offensive scheme and now a good defensive coordinator. If I were running your team I'd give the coaches a pass for this year. They get a little bit of a knock because your secondary is underachieving. The offensive is mostly hampered by untimely injury and losing two good offensive guards to the salary cap.
It's no fun to lose, but the Packers should be in good shape with a talent upgrade in the secondary and on the offensive line.
I still think that Ahman Green is solid, but it may be time to start grooming a replacement.
Patience, Packerfans.