Why can't Americans keep domestic debates to themselves?

Because "debaters" (I use this term loosely here) are looking to add credibility to their arguments. If there are other systems out there, it's useful to compare them to ours. Unfortunately you're right that there's a lot of misinformation out there. Mostly because that's how politics is. It relies on simplifying and stereotyping situations and arguments. The boring, complex reality doesn't generate votes, but "Your Grandmother is going to be killed by a death panel!" does.