"why is he hellbent on defaming God by way of an Atheist Bus Campaign?"
Why not? Sauce for the goose & all that (those putrid boards outside churches with Bible quotations)
"Is it bitter contentions?"
I hear Richard prefers lager.
"has he conformed to persecution like the ones he condems?"
Two Words: NO U
"Is he fulfilling prophecy?"
1- Create bus sign campaign
2- Fundies RAGE
3- Dawkins is fulfilled (smug)
4- ?????
5- PROPHET!
"Assuming Richard Dawkins is an intelligent man"
You know what they say about those who assume: They make an ASS out of U, not ME. Besides, he thoroughly destroyed Ted Faggard in his documentary "The Root Of All Evil?"; that, and his book "The God Delusion" have made him Public Enemy No. 1 in the Bible Belt, so they certainly fear his intellect. So there's no need to assume. He's intelligent enough to crush YOUR 'faith'.
As for those buses with those signs on them, they're mainly made of steel. Which is an alloy consisting of mostly Iron (+ Carbon, and a few other metals). You know what happened with Judah, with backup from God, when he tried to drive out the inhabitants of that valley...:
Judges 1:19: And the LORD was with Judah; and he drave out the inhabitants of the mountain; but could not drive out the inhabitants of the valley, because they had chariots of iron.
And aren't London's streets like valleys? 'Nuff said.