I don't know why the article is picking out millennials (other than that it's a popular tactic in the news media). You can replace the phrase "American millennials" with "Americans" in the headline and it will hold true.

I'm reminded of something John Oliver said during a segment of Last Week Tonight some years ago about the lottery. It seems that there are only two classes of Americans. The rich and the soon-to-be rich. At least that's what Americans seem to believe.