You've very succinctly stated where you're wrong if you think the Colonel is correct in thinking it's the flight suit that is the divisive issue here. It's not. It's the Capt ATTITUDE that is the divisive factor, not what he is wearing. His attitude drives home the standard "us versus them, "haves versus have nots", "arrogant and entitled versus hard working back-bone of the service" agendas here. That is the problem that needed to be addressed here, not what others were wearing.
Trust me, your question of "if it is so revered, why wear anything else?" would be met with a very loud and resounding "we would if we could get away with it!" response from a vast majority. Seriously, do you prefer to wear the monkey suit or the uniform that you go out and conquer the world in?
You won't see many AF aviators walking around the Pentagon in flight suits, either (except on Fridays, when even the CSAF and all the other GOs are wearing theirs). It's pretty much understood around ALL the services that their are times and places that it isn't appropriate -- working at a staff desk job in the HQs with other services or civilians outside of the DoD (like Congress) is one of them.
But the issue in question is back at an Ops unit, "in garrison" so to speak. Away from the areas where you have to "appear professional to the muckety-mucks". (Which is something I HATE working in the Pentagon. My Profession is to beak things and kill people. Why are we trying to fool Congress by dressing up in our monkey suits and primping around like its a parade?)
I get it, you don't understand the AF culture, one focused almost exclusively on airpower and its application (I try to ignore the space guys, I just don't get them
). Other services have other cultures, based on their histories and missions. I've seen the Army's, and the Marine's, and the Navy's. Haven't experienced the Coast Guard's as much, but I'm guessing I would see it the same as you see the AF's -- just a little "off".