Why do they wear raf cap badge
Quite simply - they are not part of the ATC and so don’t wear the ATC cap badge. As there is no CCF badge (army sections are affiliated to different regiments), they wear the RAF badge
While I would defend to the hilt the right of the CCF(RAF) to wear the RAF cap badge, that common argument doesn’t really hold water as there is a CCF(RN) badge so we could easily invent a CCF(RAF) one. Or an ACO one, and all wear the same; but it can’t be the ATC one as that’s the ATC one, and I can’t see the ATC giving up their badge.
It’s also because there were unofficial ‘air sections’ in school OTCs/JTCs even before the ADCC was founded in 1938, some wearing the RAF cap badge.
I suspect the screams would be just as loud from both the ATC & CCF(RAF) if they tried to make us both change to a common ACO cap badge.