My point was that the class A used to be mandatory wear, much of the year. Unless one was working on the flight line or doing other work where mechanics clothing would be appropriate. It's no accident that the old fatigues were pretty much the same, except in green, as what auto mechanics, plumbers, etc wore at the time. They were a work uniform, "blue collar" type work. If you worked in an office, you didn't wear 'em you wore class A's or something similar. In the 80s that meant the same pants with a shirt that could be worn open collar, or with a tie, depending on circumstances. (Of course that was too comfortable for certain brass, so they changed the rules to require wear with a tie, unless it was the outer garment. You couldn't wear the lightweight jacket unless you also wore a tie. Other wise at most southern bases, folks would rarely wear it any other way.
What's currently missing, but present when I was serving, is something equivalent to "corporate casual". Once the kahki 1505s (named after the number assigene to the color/shade) later it was the regular dress uniform's pants or something like "dockers", which didn't hold up as well as today's dockers, and tended to get shiny after a washing or two, with the short sleeved shirt worn with an open collar (Until the 80s that was the only sort of sort sleeved shirt we had. That one had no epaulets, rank was worn on the collar by officers and on the sleeves by enlisted). You can still wear that combination, although I'm not sure if you can wear the open collar, I've not been on an AF base in a long time, and then everyone was wearing green bags or BDUs. When our AF customers visited us at our facility, they usually wore the same, but occasionally they'd wear the blue pants, light blue shirt, but I think always with a tie. I hate ties with a passion!
No blue uniforms anywhere...the AF projects a "warrior" image now...BDUs or deserts everywhere now...