Dawkins use of Holocaust deniers as an anology is simply down to his view that evolution as a theory has been proven beyond reasonable doubt and that anyone who denies the development of life on earth through the general evolutionary process is exhibiting a similar stubborness to accept a commonly held fact as someone denying that the Holocaust took place. I believe he also qualifies this in The Greatest Show if memory serves me right.
It is fair to say that in areas where he is convinced of the validity of a given theory he is passionate about this. It is also fair to say that his views on the dangers (as he sees it) of giving creationism an equal footing with current evolutionary theory in education are strong and he is not backward in coming forward to express them. He is also skeptical of any sort of view that there could be supernatural answers to open questions. His view is that is there is nothing that is not (or probably will not be) ultimately explained in a scientific manner and we do not have to revert to the supernatural.
There are differences between this and the sort of attitude demonstrated by religious fundamentalism however.
Firstly, the passion with which he expresses his views is no different to how any person may express their views on a subject they feel strongly about. If an employee and union member expresses their views on their employment contract and takes strike action then are they a fundamentalist, or simply convinced of their opinion?
Secondly, he is a scientist and open to changing his views should appropriate information come to light on the basis of valid scientific research. If it was proved in a scietifically valid manner that there was a supernatural explaination for some aspect of the natural world then he would be honour bound to accept it. Again, I believe he has said as much. This is very different to a religious fundamentalist who simply refuses to move from an entrenched position because it is unreconcilable with what commonly accepted science has to say.
I am sure that he has preferences for one or another position where conflicting hypothesies (sp?) exist. I would agree that sometimes he come across as superior and sneering at those whose viewpoints he disagrees with. Does that make him an entrenched extremist? Not at all, just human.
