Thae fact is, if you had said that Dawkins goes overboard, that he's virulently and intolerantly anti-religious, I doubt you'd have gotten much reaction except agreement. Claiming the 9/11 attack was a result of 'religion', as opposed one violent sect of a notably violent religion, is a gross oversimplifcation. Sure, promoting passionate belief in an afterlife is a tool to get young men to immolate themselves, but Dawkins, if he were applying the same degree of honesty to his social criticism that he applies to his science, would have noted that most other religions do not generate large numbers of suicide bombers, and so 9/11 seems to have been a result of Wahhabist Islam in particular far more than of religion in general. One could then go on, if one wished, to make a more moderate case that some other religions, including some sects of Christianity, have been accompanied by serious but not as extreme or vicious violence.
I grew up in England and Ireland. In England, in particular, 'stamp out' is used in contexts from 'stamp our racism', where they really might mean state action, to 'credit-card companies should stamp out deceptive practices', where they're referring to voluntary behavior. And everything in between. It really just means 'end' or 'eliminate', without any necessary condition of compulsion.