I would definitely wear a kilt to interview. Now that I wear a kilt daily I would be pretending that I am somebody I am not if I went for interview in trousers. The interviewer can see the kilt and ask about it if they wish. I'd explain that I normally wear a kilt but that if the job called for it, for example for health and safety reasons, or was a uniformed job or involved climbing ladders, then I would be prepared to wear trousers to work even though not my normal attire.