Philosophers as Experts?

Anal Philosopher observes this:

There is a disturbing tendency among philosophers to think that their technical training—we're nothing more than logicians—qualifies them to speak with authority on every issue. In fact, the contribution of philosophy to public affairs is quite small, which is why few laypeople can name even one living philosopher. For those who are interested in such things, I recommend Richard A. Posner's book The Problematics of Moral and Legal Theory (Cambridge and London: Harvard University Press, Belknap Press, 1999).

Comments?  Also, has anyone read this book from Judge Posner?