This was clearly written by a pedant of the worst kind, boasting of how great he and his friends are at "mocking people who denigrate the passive without being

This was clearly written by a pedant of the worst kind, boasting of how great he and his friends are at "mocking people who denigrate the passive without being able to identify it". It is understood by basically everybody that there are two different things meant by passive vs. active: on one hand, the technical grammatical distinction, and on the other, the broader spirit of the phrase. Edge cases are very easy to construct: passive clauses where the agency is well-identified, and active clauses where responsibility is totally diffuse. This technical clarification is needed by nobody, because a rule-of-thumb like "avoid passive voice" is meant to be used holistically, not literally. At the end, a parting shot is fired at George Orwell and E.B. White. Naturally, the superior intellect of the author of TFA is driven home.