Push The Button wrote:
In "Encounter at Farpoint", Q appears on the bridge in an American military officer's uniform (Army or Marine Corps, I forget which now). Picard snaps at Q about the "costume" he is wearing, which I have always found to be extremely offensive, as if anyone that was serving in a uniformed service prior to the existence of the enlightened ranks of Starfleet is some kind of barbarian or crackpot. Picard never applies this judgement to his own ancestors' military service, however, most notably the Picard that served in the battle of Trafalgar. Hypocrite.
Folks from the present (relatively speaking) are usually, if not always, going to see themselves as superior to their predecessors and lots of things about them. Folks today would look back at the kind of clothes Aristocrats wore back in the past (including the makeup they wore, including men) and see them as ridiculous costumes as well.
It's not Picard being deliberately insulting, it's just how a guy 300+ years from now would think of our own attire including what our soldiers wore.