BEEDEE:

Aye, before even daring to post this, I'd gone over Matt's articles, and not just once! However, I never found anything speaking to the whys and hows of the adoption of the great kilt.

Sigh. Maybe I'm simply not meant to know.

EDIT: And MacMillan of Rathdown lends credence to my theory! Maybe I am meant to know (or at least to make reasonable surmise, which is not the same thing, of course). Thank you, sir, for the information.