Armed forces are the legitimized monopoly of violence which are for better or worse absolutely necessary for the nation states of today and any time in the foreseeable future. The military's rigid command hierarchy and strict rules and ideas of duty really don't have any place in free society outside that monopoly. While it is absolutely necessary in a military to have the actions of many people dictated by the will of a single person, outside of that environment the necessity would be artificial and arguably the situation would be tantamount to slavery.

In other words it just isn't possible to recreate the structured existence of a soldier outside of a military force without extending the military well beyond the external force it must exclude itself to or legitimizing pseudo-slavery conditions. The costs of military upkeep are likewise very justifiable. Not that everything the military does is good or necessary, but the baseline of _having_ a military is fairly universally accepted as needed. Making up something else would look like a handout or a cost center and wouldn't stand up to the test of time and support.