The reality as senior officers knew was that the kilt is entirely unsuitable for modern warfare-yet at the same time they were faced with the reluctance of the kilted regiments for romantic reasons to give up the kilt when on active service.

Having said that there were instances of individuals wearing the kilt in all campaigns during WW2. Here a story to terrify all kilt wearers-of John Masters on a Chindit expedition using his intelligence officer's kilt[whilst being worn] as a blackout curtain so he could examine a map by matchlight when in close proximity to a Japanese position!

I do think there is a vital role for tradition to play in the maintenance of military morale/recruitment. However the kilt should be likened to American cavalry officers wearing their campaign hats [circa Indian wars]-not entirely appropriate for in and out of vehicles/helicopters-or when bits of metal are in the air.
Hence the reasoning behind swatches of tartan worn behind cap badges on bonnets, or as a shoulder insignia -- that way, a little bit of the kilt is still there on the modern uniform.

James, was the story about John Masters from "Bugles and a Tiger", or "The Road past Mandalay"?

Nice analogy, btw, about the Cavalry slouch hat. Many forms of "ceremonial" dress were actually practical pieces of uniform at one time, and now, have become a symbol of unit pride & tradition.

Cheers,

Todd