Dawkins has been arrogant for years, a man so convinced of his intellectual superiority that he believes the one domain in which he happens to be an expert, science, is the only legitimate way of acquiring or assessing knowledge. All of his outbursts in recent years follow from this belief: he understands the scientific method, a process intended to mitigate the interference of human subjectivity in data collection, as a universally applicable way of understanding not just the physical world but literally everything else as well. Hence his constant complaint that those appalled by his bigoted vituperations are simply offended by clarity; feeble-minded obscurantists who cling to emotion, tradition or the supernatural to shield themselves from the power of his truth bombs.
You don’t have to be religious to find this level of hubris baffling.
But it’s not baffling, really. Dawkins gained fame and fortune through his vehement atheism. It’s worked so well for him, why would he not want to atheist as hard as he can? It’s a pretty common tendency for humans — to lean hard on the things that work for them.
Look at it this way: Let’s say that you’re a big, big fan of vinyl siding. You put it on your own house, and you think it’s fantastic. You love it so much that you take a job selling it. Since you’re such a fan of the product, you’re really good at selling it, which makes you a lot of money, which makes you love vinyl siding even more. As this cycle continues, your fanhood and your livelihood would eventually become inextricably intertwined. It would be the subject of every conversation, the solution to every problem.
Dawkins’ existing beliefs have been reinforced by success and acclaim, so of course he leans on those beliefs more and more; in his case, apparently, to the exclusion of everything else.
Maybe everyone’s not as obnoxious about it as Dawkins, but there are variations on this theme everywhere you look. Like the White House, for instance, where a guy who got where he is through community organizing tries to run the country like a community organizer. Why would he not? Vinyl siding has worked on everything so far.