That reflects an American vs English cultural difference more than a personal difference in style. Dawkins comes across as a jerk to some Americans. He is a brilliant man whose ideas changed the paradigm in his field. He is also a product of the UK college system that applauds brilliant debate. We don't even teach debating here. Dawkins tends to write in a debater's style as Tyson points out. Dawkins is not being argumentive, rather he is advancing his theory and countering opposing ones.
Of course this goes against the assinine idea common in Canadian and American schools and society at large that everyone should be heard. Actually lots of people are fucking idiots and their opinions are not worth shit. If that hurts their feelings, tough.
American and Canadian schools pander to slower students at the expense of the brighter ones. Teachers spend too much time helping the slow learners and the entire class is stifled. English and Scots schools are much more ( or were, in my time) into streaming students as per their ability. Academic excellence was applauded and the competition was fierce to get into the better schools. Over here this only starts to happen around grade eight or nine.
FYI I went to school in Vancouver and Glasgow. My father taught at University in Scotland and Canada, he was on the Vancouver school board while I was in high school.