I think that he, in common with a number of Media Darlings, like the sadly missed Christopher Hitchins, do not sneer at the person holding silly views, but at the views themselves, there is a distinction.
I too do the same thing, I would never denigrate the person themselves, but if their views are way off, I will point out why and where.
The problem for rationalist thinkers is that many believers simply will not consider the evidence in an open-minded way, just look at the JW attitude, and many believers are like them, blinkered, ill-informed, not prepared to use Critical Thinking skills and very ready to make Ad Hominem attacks when they see they are losing the debate, i.e "You are only an Atheist because you do not wish to Blah Blah whatever..."
I can understand the frustration that Richard Dawkins feels with people like that, he has worked hard to make quite difficult Science accessable to the common man, and yet they will not even give his work the attention it deserves.
The Greatest Show on Earth is a truly great book.