Joe, whatever the case might be for punctuating as the British do, the explanation for the ubiquity of the British style on the internet is surely not the necessities of correct computer coding. How many ordinary bloggers have ever written a line of code in their lives? As for Ben Yagoda’s second reason–it “makes more sense”–this is an opinion and not an explanation. It makes more sense to him, and to you. Not to anyone well-schooled in American (that is, correct) style, for whom these misplaced quotation marks outside periods and commas are a jarring sign of either a slapdash education or sheer laziness.
I started teaching college students in 1981, before the internet could be blamed for anything. I’ve seen such errors, and many more besides that cannot be excused with the claim that they’re correct “somewhere else,” in all the years since.
But while we’re wondering aloud what the editors of First Things would be willing to change, I am here and now making it my personal crusade to change the magazine’s house style on the formation of possessives of singular proper names ending in “s.” No more of this “Aquinas’ thought,” please: make it “Aquinas’s thought.” We don’t have to be total Strunk and White sticklers, but listen up: if you say two distinct ”s” sounds, spell two distinct ”s” sounds, with an apostrophe between them. And no one says “Aquinasssssssssssss” for the possessive.