Dawkins problem is that people stopped asking him for his expertise and started asking for his opinion. He is the victim of society's willingness to appeal to authority[1]. While he's a fantastic scientist and thinker on the topic evolutionary biology, he isn't a particularly great communicator when it comes to everything else. Outside of his subject he doesn't explain his ideas well enough. He should be communicating at the sort of level a layman would need in order to understand what he's talking about, but instead he leaves giant gaping holes in his arguments because he doesn't feel he needs to explain himself in. Consequently he's often misunderstood.

[1] http://en.wikipedia.org/wiki/Argument_from_authority#Appeal_...