...nothing to do with puritanical...

I thought so too and that they were incorrectly referring to Protestant work ethic. Turns out to be the same thing.

The Protestant work ethic, also known as the Calvinist work ethic or the Puritan work ethic, is a work ethic concept in the social sciences, particularly sociology, economics, and history. It emphasizes that a person's subscription to the values espoused by the Protestant faith, particularly Calvinism, results in diligence, discipline, and frugality.
[...]
Those with the ethic believed that good fortune (e.g. from hard work) is a vindication of God in this life

Still dumb to say that hard work is good because it is hard but some bad ideas die slowly.