Your comment has made me realize just how easy it is for people to misunderstand each other, due to attaching different meanings to words. Of course "unique" means "distinctive" to most people. I had just managed to completely forget about it, and assumed that everyone shared the computer science meaning of "unique".

I wonder how many arguments ultimately boil down to this kind of misunderstandings over words. And it doesn't help that marketers will happily use loaded words like "unique" to create hype.