That's the term people use to describe Americans claiming to be something else (especially two or more different things like Irish and Scottish), precisely because it's descriptive of America's demographics while also being irritating to American's like yourself who want to claim to be something else. It's no one's fault where they are born, raised, or where their family comes from. So why try and lie about it, or twist it? It just doesn't make sense to me.

Also fyi mutts are the healthiest kind of dog there is, because they have the least inbred genetic traits. Having genetics from multiple origins isn't a bad thing biologically speaking, it can actually sometimes be beneficial.