You can get rich on salary. I think a portion of us are making more than 200k, 300k, or even higher in income per year.
[1] http://www.businessinsider.com/us-census-median-income-2017-...
Two full-time incomes for a household, you can easily get to $85,000 to $120,000.
What you're referring to, includes every person that generates any bit of consequential income. Part-time workers, or people earning $8k-$10k over the Summer, are included in the total median figure (which is closer to $30k).
So, several million Americans are making 1/4 million + per year before taxes. Which is why millionaire does not really qualify someone as rich anymore. Consider 1 million in 1915 is the equivalent of ~25 million in 2017 which is closer to what most people think of as rich.
Well, you weren't either so it seems fair. "1 in 20 people make over 200k / year" -> As you probably meant full income earners it would be interesting to see what it would be if measured actually for "people".
So, they may not be making 420k exclusively from their job, but 200+k / year is surprisingly common.
WSJ's number is individual not household, and ignores people making $0, most of home are likely in a household with an income-earner.