I suppose I didn't clarify this quite enough--it is in there, but the article is long, so it's easy enough to overlook. Anyway, I'll elaborate a bit here.

The point is not that philosophers should understand science (unless they're making empirical claims that are directly addressed by science). Rather, philosophers should understand the scientific method, should understand practical epistemology, because it is relevant to so very very much of the philosophical endeavor.

Failing to do so can be both corrosive to society, in that philosophers advance complex and compelling arguments that, when you dig into them, are actually wildly counterfactual and/or logically indistinguishable from nihilism; and can prevent the philosophy from having any relevance in advancing human understanding despite having brilliant people thinking in sophisticated ways.

As a philosopher, if your epistemology does not account for or at least admit the unreasonable success of the scientific method in the face of the relative failure of pretty much everything else, then you haven't really met the minimum standard necessary to talk about science, society, knowledge, morality, etc. etc..

If you want to speak to a specific area of empirical knowledge, then as a philosopher you probably need to have an educated-science-literate-layperson's knowledge of the area. But details matter. If you're trying to make metaphysical arguments on the basis of interpretations of quantum mechanics, but you don't understand the mathematics behind quantum mechanics and the experiments that are explained by that math, it's awfully hard to say something useful.