Garner's Modern American Usage: style guides defunct?

When I first started reading Bryan Garner on legal English, little did I know he would one day write a book on American English usage. This is a book that has a recommendation on the cover by William Safire and came out in its third edition in August. Here it is at amazon.com. You can read his defence of his prescriptivism in the preface there. I hope this doesn't keep him away from legal usage. But perhaps, having written on that subject and revised Black's Law Dictionary, he has had enough of it. At all events, Bryan Garner has sent out a call for his readers to buy one or more copies of the new third edition at www.amazon.com or www.bn.com This is because the main U.S. bookstore chains are not stocking the book and they have told OUP that they consider usage guides a "defunct category". It might be even better for Americans to go to their bookstore and order it. Or why not order the Chicago Style Guide, or, for Britain, New Hart's Rules, or Judith Butcher on copyediting? Here's a Wikipedia list. I'm not sure what the situation of British bookshop chains is, but I suppose even if Germany is being Thalia-ized, the Duden is safe. Here's the rest of Garner's email, which someone sent to me: If you’re curious to see what effect you’re having, watch the rankings on Amazon.com or Bn.com in coming days and weeks. We’ll be alerting the major chains to those numbers, and we want to get as close to the top 50 as we can. If you're trying to order and see that the book is lab…