THe best reason, I think, to keep Mularkey is that there really isn't an abundance of coaching talent out there this offseason. JIm Fassel, Haslett...this is scraping pretty low. Wade Phillips is considered a hot prospect, and ex-bust Gregg Williams was the holy grail.
Next year, you can get a little more seasoning into some of the outer coaching prospects, and not have to deal with such a mad rush for a few guys.