So the response is not to defend avoiding military service but to launch into personal attacks of your own? Good plan.
I don't understand why you have a problem with the response; I mean, the original chickenhawk argument isn't substantive at all, so the grounds have already been shifted to personal. The idea is to beat the people who make this asinine argument over the head with it until they acknowledge its invalidity.
And you're absolutely correct in that I will not "defend avoiding military service." It's rather silly to go on the defensive when you don't need to. Being on offense is a lot more fun; you actually get somewhere when you're on offense.
So excuse me if I don't allow people to frame a debate on the merits of US foreign policy around my career choice.