Devils advocate asks: so maybe it's diversity that causes higher murder rate, not guns? Switzerland has very low crime afair

I totally got your point and you actually convinced me of it. I do wonder though if given the diversity and disparity of income banning guns wouldn't help getting the homicide rate down. Even though the guns aren't causing the issue (as you well demonstrated) they might be exacerbating it. We are not gonna make the US magically less diverse and unfortunately won't close the income gap over night.

I was still curious though if there are other countries with the same diversity and wealth gap. That's what prompted my original comment.