Ah - you must remember that a lot of dangerous work took place in those factories. When the internal combustion engine became popular in Scotland, it soon became clear that the traditional kilts worn for everyday assembly line stuff such as the manufacture of cathode ray tubes, whisky, and the celebrated eight track cartridge player would have to make way for more practical garments less likely to call into question Health and Safety at Work issues !

The 'manufactories' didn't arrive until the Industrial revolution was well underway. In the U.K. this mainly involved the making of heavy machinery and linen.

Whilst much of the machinery, it's true to say was made in Scotland, most of the linen was made in Lancashire (North England). Queen Victoria may have popularized the garment as dress wear among the nobility - but surely not among the mass of working folk ?

I still can't see how the timeline for this theory fits.