Yes, I am an American and therefore am genetically incapable of knowing anything about kilts and tartan, no matter how much I study the subject. On the other hand, I was born with an amazing amount of knowledge about cowboys and baseball. :-)

Seriously, I sometimes encounter this attitude myself, usually (though not always) from native Scots who have some deeply held opinions regarding their national dress.

If it can help, I can always point to the works of native Scot tartan scholars to corroborate my own writings. But really, there has been so much good, accurate information regarding the history of the kilt made available lately that people really do have no excuse for persisting in ignorance (no matter their nationality).