Try reading the excerpt, which says, in part: "The main reason scientism has the following it does is probably that people are, quite rightly, impressed with the technological and predictive successes of modern science. The trouble is that this simply gives us no reason whatsoever to believe scientism -- that is to say, it gives us no reason to believe that science alone gives us knowledge." And, mind you, that is a much reduced from what is said in his books.
Atheists here like to muddy the waters by drawing the discussion away from what theists are saying by inferring things that are not, in fact, being said at all. I don't know whether they do this simply because they like being argumentative, are incapable of understanding what's being said, or because they believe that in order to discuss God and religion at all, it must be on their terms and according to their definitions.