Why do teams fire quality Coaches and replace them with tards?

[rubbrband]

Example #1
Fire 14-2 Schottenheimer because he can't beat the pats. Afaik no one has done a very good job at beating the pats the last 5 years. And who did they hire? Norv Turner, this guy has been a miserable head coach many times over. I thought in the past he was at least a good offensive coordinator but am beginning to doubt that.
Example #2
Steve Mariucci was replaced not only once but twice by far inferior coaches. The 49ers continue to make stupid mistakes like this by letting Garcia and Rittay go for Alex Smith.

I'm not totally against the idea of letting a good coach go if he isn't getting the job done, but you better have a pretty good replacement in mind. Good examples of this would be Chucky replacing Dungy and Gibbs replacing Spurrier(resigned).

There may be some good examples of this in other sports but The Coach in football is just so important.