Are Strunk and White overrated?

It's been fifty years since the first edition of Stunk and White's Elements of Style was first published and since then millions of high school and college students have pored through it, searching for the answer to their split infinitives and passive voice. However, is it overrated and even unhelpful to the degree that it's positively bad for one's grammar? The head of Linguistics at Edinburgh University thinks so and he has written a screed against the grammar guide that is well worth the read.