The gray area and issue is in someone not being able to tell a PV kilt, or something like that, from the traditional wool kilt when someone else is wearing it.

For example, someone is wearing a tartan PV kilt with sandals and without a sporran. Someone else sees this and is then offended because the first person is disrespecting the traditions of Highland attire, and the national dress of Scotland.

If the person is instead wearing a canvas kilt of some sort with sandals and no sporran, there is no disrespect to Highland attire and the national dress of Scotland. That doesn't mean the second person won't be offended, but the non-traditional canvas kilt is not Highland attire.