The need is there.
I'm serving right now. As the military is acting in mostly an advisory role in Iraq, there are times when your m4 may not be at your side, or being mounted in a vehicle restricts your use of the m4 while your door is open. There are a lot of meetings where keeping your m4 at the ready offends the the people you are trying to coordinate with. I know, you're thinking screw them, "it's my life at stake", but the reality is we're having to comform. Seems like complacency, kind of, but it's not.
I'm fine with the M9, but a 1911 would make me feel a whole lot better. It's like your PD weapon. You could go your whole life without having to pull it, but it's that one time you're glad you have it.