By looking at the quality of clothing that Wal-mart already sells, if they sold kilts they would be poor quality that may only make it through one or two wearings. When folks are interested in cheap junk, they usually find it at such establisments. Unfortunately, Wal-mart has found its niche and at times can be the only resource.
Personally, I would rather tie pillow cases around my waist and call it a kilt than to buy something like that at Wal-mart.