I had a long time Apple user ask me if I had a Mac or PC. I was using Ubuntu Linux at the time, so I said PC :P
The term "PC" persists not just for historical reasons, but because its hard to come up with a replacement term. A "Mac" refers both to hardware and the OS, whereas a "PC" means "Windows OS running on Windows-compatible computer". I suppose we could replace the term "PC" with "WOS-ROWCC".