I think you are being a little unfair to these chaps.
Meet them in their daily jobs and you will see crisply ironed shirts and smart pants. I've never seen better turned out instructors anywhere but C*** A***. And the quality of instruction is also very good before the naysayers jump in.
The problem comes when you go on a fly out. You don't want to look like a knob walking down the street with bars and stars on but the company says you must wear uniform. Inventive instructors 'combine clothes' to meet most occasions. (I suspect the shirt over t-shirt allows a swift change from action man to ordinary man)
I think the company should have just said 'casual allowed for the flyout' and you would never have known.
Pop along to one of theses schools and swoon at how well they are turned out.