The fact is, whichever side of the fence you are on, Starfleet does not have a equivalent to any modern military. It's mission purview is so outside of any Earth-bound experience, it makes any direct comparison impossible.
It has been referred to ON SCREEN as both a military organization AND non military. Most of the military evidence comes from the TOS era, like Kirk specifically claiming he's a soldier, them using military courts-martial etc, a science-vs-military argument in TWOK. Roddenberry's original pitch included the reference to Horatio Hornblower, stories of a military officer on a military vessel. How much of that was his real intent, or just flim-flam to try to sell the series to TV execs who wanted an action show, I doubt we will ever know.
What is plain is that his statments then changed, and everyone tried to conform to the new "not-military" directive.
The argument does seem to just be going around and around in circles, and IMHO it will never lead to a true consensus as all we can do is state the "it is" and "it isn't" statements, both of which are just as valid as the other.
Starfleet is therefore either a military organization, who due to the nature of a space service, spend most of their time in an exploratory and/or scientific role.
Or an exploratory/scientific organisation, who due to the nature of a space service, are also responsible to undertake the responsibilities of the military arm of The Federation.