I think there is a good reason why Richard and other atheists are considered "shrill".

Richard and many other atheists focus on the factual. They are trying to engage in a rational discussion. To persuade through evidence.

The perception however by the believer is more like a total stranger coldly explaining that your partner and family are cheating on you. It is perceived as totally negative ( about the person/God) and perceived as an opinion. It only leaves the listener emotional, angry and insulted and protective. They are no longer in a rational state of mind. From a practical strategic point of view this is why it might be advantageous as atheists to push the more positive side of atheism.

From atheism we are all immediately faced with the following conclusions 1) No (absolute) purpose to our lives 2). No after life (only our own life and only today) 3). No absolute morality 4) We only know things through our own testing

These conclusions immediately urge us to be reasonable, to live today, to appreciate life and love.

In the end these qualities may be more persuasive for many believers then even the most rational of arguments.