Because young upstart coaches end up winning Super Bowls a lot more often than old coaches that won a Super Bowl 2 teams ago. I know McCarthy's credentials look appealing, but he's no longer in his prime. If he's the hire, I hope he proves me wrong. However, history states that Brady or some other new coach is more likely to lead a team to the Super bowl before McCarthy does.
This board is wild. In one thread, people are mocking the Cowboys for being the only team to not reach the NFC Championship game this millennium, in another people are screaming hire their coach!