Well, it wasn't me.
S&W are exalted by being recognized, not by being expert. I consider debunking S&W no more iconoclastic than calling into question Dr. Phil's expertise on relationships. Much as with Pluto's planetary status, the brontosaurus, and the oft-misunderstood "the exception proves the rule," we cling to "facts" we were told we could rely upon, with perhaps less than ideal understanding of the logic, and yes, rules, that underlie the learned consensus.
The main value of S&W is that it will teach you the style that everyone else has been taught. It will not, however, teach you correct grammar, nor does it admit to much in the way of geographic variation in English, i.e. how it is written in England. It gives senseless and archaic advice that was perhaps practical at one time, but which has eroded in value, such as the distinction between classical names and non-classical names and the possessive S. That rule only existed because people continued to read books with archaic and irregular possessives, such as popular versions of the Bible.
Not only do they malign the passive voice, but they do no not understand it. Thanks to their dubious advice, modern software still reliably identify adjectives such as "confused" as though they were verbs.
When I want to theologize English, I prefer Fowler's. Even his British English is arguably more useful than S&W, since his usage, grammer, and linguistical command are better. And as for vernacular, there is no better grammarian than Google.