Speaking of the Amish, I was advised by folks when I moved to Cincy that I should check out "Amish furniture" because it was well built and cheap. So, I ventured out east one Saturday to see said Amish furniture in shops etc. I found two, and both were labeled as Amish, and the folks there were no more Amish than I am. One lady admitted to me that they just had a wood shop out back building furniture and they didn't care who did the work for them. It was marketing. I'm sure some actually was made by the Amish, but most, probably not.
I gather they did not trademark the term.
It's a bit like terms like Champagne used to be, or Chablis, or Hearty Burgundy (which is a bit of an oxymoron).
What is the etiology of the term "oxymoron" anyway?