Dawkins presumably uses extreme language because he's challenging extremists.

Most religious people I know are not extremists. They just get on with living their lives the best they can and trying to be good people – just like most non-religious people I know. They accept science and education, and decide for themselves which parts of their religious scriptures hold what they consider to be fundamental truths, and what should be regarded as metaphor. So far as I am concerned, that is absolutely fine – it is no concern to me what they choose to believe in. To me, it's like having an interest in stamp-collecting or golf – I don't see the attraction myself but understand that some people do.

However some religious people want to impose their views on the rest of us. Even moderate religious organisations seem to believe that their views should receive special consideration when public policy is being considered. The more extreme insist that their views should receive special treatment – for example, those who insist on creationism being taught in schools (but only their version of creationism of course). At its worst, religion is hostile, even violently so, to education and free thought, not mention personal freedom.

Of course it's not just religion which can be oppressive, intolerant and restrictive. However religion exercises enormous influence over millions of people. For the most part, that influence is benign, even positive – I don't undervalue the good things done in the name of religion, but repeat the point that religion is not a prerequisite of doing good things. However, all too often that influence is malign, oppressive, violent and dangerous. You may say that's the fault of the people interpreting it rather than of religion itself but the effect is the same.