The point is it's about time horizon. The parent would decide that in early days of Higgs' career, he wasn't productive enough, and thus he would prevent him making the discovery for which he is famous. Likewise, at the time Verlaine, it would be more productive if he was just sent to war.
But from a longer time horizon, nobody really cares about those people in the 1950s having to support Peter Higgs living, or about people not having Verlaine in the army. We care about their results differently now.
I wish that timescale is the one thing that people who use the word "productivity" or "efficiency" would understand. There is no universal optimum, it depends on the time horizon you're looking at.
And while I am at it, let me make another comment to the article. I think today, we are so obsessed about efficiency of other people working, because there simply aren't enough jobs for everybody (due to automation). Since having a job (in a general sense) is customarily a requirement to being fed, most humans optimize towards not actual productivity, but an appearance of productivity. All these attempts to measure productivity are just a symptom of this problem - we desperately need something with which we can bang people in control of resources over their heads with, so that we could eat.
In other words, most jobs are changing from doing actual work into proving to other people in society that you did, ever so diminishing, amount of work. It's a shift in the focus of the competition, and unless we collectively realize that we can just lay back and don't need to actually compete, it won't get any better.