You didn't have to say it: it's inherent in your argument that military service, if it involves deployment - which in today's world we must assume it does - is incongruent with having a family.
It's not incongruent if one parent is deployed while the other remains at home with kids--that is a reasonable sacrifice people have made for ages. But if parents are divorced, and one leaves for an extended period, it should be expected that the other one will gain (and continue to have, in the interest of stability) a larger role in the children's lives.
Except we aren't talking about all military, are we? We are talking about military folks who were either 1)never married (which is detrimental to having a healthy family) or 2) divorced (which means the family that they had wasn't very healthy).
So I'll agree that a person with an unhealty family situation, who happens to be in the military, may not be the ideal parent.
And now I'm out of here for a good while, but if you want to continue, I'll be happy to pick it back up when I return to the computer.