I think he could have presented the same facts (and even the same opinions) more effectively without all the venom against religious people and sense of superiority

I don't actually understand this bit. I've heard the argument being made many times, yet no one seems to be able to pinpoint what they mean by it.

Here's a recent example I can think of. Richard Dawkins said a little while ago that early bible writers were ignorant of certain facts we now take for granted. People reacted to the "ignorant" bit, to which Dawkins asked "Do you know what the word ignorant means?" This is a fair question; do you know what the word mean, or are you reacting because your knowledge is lacking? I often find that people are fuming more over clear writing than over fuzzy language, even if there is no real venom or sarcasm or superiority within. (I could go into a tirade about people getting offended at mere words, and whether people generally fully, truly understand what it means to be offended, again with pointers to the identity comments at the top of this post!)

I can discuss with people - say the change of musical styles from the renaissance to the baroque in early Italian music (and the early influence on German music through Schuts) - and rightfully and without any venom say that most people are ignorant of the issue. It's not an insult, it's a word describing a lack of knowledge on something (knowledge I'm not proud of, btw, as my geekery is a negative liability in society ... more on this one later). I am myself terribly ignorant on a number of issues and subjects, and have no problem admitting so; I use the word for what it means. Yet people think it means a negative when it really is neutral. (Same problem with liability, btw. Something can be a liability to you, but there's positive and negative liability, and we often just say "liability" and draw a negative over anything we say by being less precise)

I think Dawkins attempt to be precise is often misinterpreted as having some negative connotation they read into it. (Hitchens is another chapter all-together, of course) I think, in general, that people should strive to be less wrong in their own reaction to the world. Things would quickly be a far gentler place.