I would not quite say that progressives are [quoting Matt Yglesias] “against such an ethos,” but where does it stand in their pecking order? Look at fiction, such as famous left-wing or progressive novels, or for that matter famous left-wing and progressive movies. How many of them celebrate “an ethos of initiative, hard work, and individual responsibility”?
Being a conservative, almost synonymous these days with intellectual dishonesty, Cowen simply fails to engage with Yglesias' main point: the conservative focus on the work ethic is fundamentally dishonest. The rich are prosperous; virtuous hard work causes prosperity; the rich are therefore hard-working and thus the epitome of virtue. The fallacy should be obvious, at least to anyone but a conservative.
But Cowen's question does have some merit. I don't know about other progressives*, but while these virtues are important, I don't see them as at all problematic. People already have initiative, they work hard, and they take personal responsibility; we don't need to "sell" these virtues any more than we need to sell cleanliness or not fighting duels. The problem that we have today is not too little personal responsibility but too little social and mutual responsibility. We emphasize virtues not by their intrinsic importance, but by the difference between their importance and their actual implementation.
*OK, I'm not really a progressive. But I have a lot more in common with progressives than with conservatives.
With sufficient initiative, hard work and individual responsibility (or cunning, duplicity, and ruthlessness) one can fight one's way to the top 10% or 1%. We can say with at least some accuracy that those who are at the top have more of these virtues than those in the bottom 90%. I don't find it objectionable that these virtues should be rewarded; what I do find objectionable — aside from the obvious hypocrisy of extolling the virtues of of hard work by those who have achieved prosperity without it — is the notion that if you do not have the most initiative, if you do not work the hardest, if you are not in the top 10% or 1%, then you are by definition dependent and lazy; if you then complain, you are merely being irresponsible.