For the same reason you choose one font over another: the aesthetics of a text matter, especially to publishers. Now, I should add that for an article that is

For the same reason you choose one font over another: the aesthetics of a text matter, especially to publishers. Now, I should add that for an article that is specifically about language, and even has some illustrations of the meaning of these diacritics, this is almost certainly a bad choice on the NYT's part. But as a general rule, I think it is defensible.