I know WHY they're selling them... that's about the width of scrap fabric unused from the middle section of the material. They can make money off of their scraps.

USA Kilts also sells sashes similar to this, but NEVER advocate them for men. Sashes are for women. These aren't fly plaids or even 'mini fly' plaids... they're sashes.

I have had men come into the store and put the sash on the counter to buy with their kilt and have TOLD/convinced them not to buy it OR to buy it and give it to their wife to wear.