Yes, people do tend to think that differences like these are environmental (such as formal training early from early on), likely because their moral system insists on it. We like to believe meritocracy is a fair system driven primarily by your own decisions. But if you don't come by your merits with hard work, meritocracy stops sounding like a just way of deciding who gets to have a good life and who doesn't. It's clear to me as the nose on my face that education is a small piece of the merit puzzle. Not nothing, but it can be rectified, unlike the situation where you are lacking the brainpower.

I was mainly talking about physics to color my opinion with my personal experience. The truth is, I know I'm smarter than most people, and I am fairly certain that intelligence is actually a significant hurdle that keeps people from being competent at my job. I disagree with the content of the article. Plenty of people are not smart enough to fill roles we need or to hold down a job that pays well.