This is purely an opinion, but I don't think the majority of Scots would be offended by non - Scottish kilts. I think you will find that there are some Scots who own and wear Utilikilts, USA kilts, etc.

As Hamish would say to anyone that puts off wearing a kilt because they are not Scottish, "Nonsense! Anyone can wear a kilt." I view the non-traditionals as a natural evolution - relatively inexpensive, washable, practical, and so forth.

Darrell