Really, you think 2 years is enough time to decide whether or not a coach can take us to a playoff victory?
So, after Bill Cowher went 11-5 and 9-7 and had no playoff wins in his first two years, you would have sent him away?
If Mike Holmgren came in and started his tenure in Dallas as he did in Seattle, going 9-7 and 6-10, you'd send him packing?
Is Shannahan was named the next coach and he started at 8-8 and 13-3, with no playoff wins, you'd say he couldn't get the job done?
Axeing those guys all would have been a mistake. But, but, Wade has never won a playoff game! He's been to 4 playoff games and was a "miracle play" and a Crayton drop away from having 2 notches on his belt. You really think the fact that Wade's Bills gave up the Music City Miracle is evidence that he can't win a playoff game? If you can win regular season games against quality opponents, then you can also win in the playoffs.
When quality teams face each other, there's about a 50/50 chance of either team winning. Let's say that was the case in all 4 of Wade's postseason losses. Saying that he lost is evidence that he can't win is like flipping a coin 4 times and getting heads each time and then saying that you can't flip tails.