The article is nice and well articulated, but I'd argue exactly the opposite on this point. The author seems to confuse equality and equity. He takes the Netherlands and Bay Area as an example and don't make a compelling argument as to how and why paying differently those employees is akin to discrimination based on race.
Were you to pay the same salary in Netherlands and Bay Area, you would effectively either (i) pay absurdly high salaries to your dutch engineers, similar to what the prime minister earns or (ii) pay absurdly low salaries to your Bay Area engineers (to the point that you'd basically have none of them).