I know what you mean.

2010, 2011 and 2013 were perfect opportunities for us to get another super bowl and we messed up all of them!

Lost to a 7-9 team in 2010 playoffs
Destroyed teams all year in 2011 and then unravelled in the playoffs
2013 defense finally became top 5 and the offense couldn't even manage a first down vs Seattle.

I agree to some extent that if we have a disappointing season this time around it may be time to go in another direction in terms of head coach.