You put more effort into crafting books than blog posts; the difference can be enough to make you sound like a completely different person.
For all we know, he writes books that sound like his blog posts, and these get "cleaned up" in the editorial process.
If you thought fame went to ESR's head, you're wrong; he was always like that.
I don't think he's done much since then that was worth writing home about, but that doesn't take anything away from that particular accomplishment.
CatB, although anecdotal, is trying to make a coherent case from evidence, and the author's ego is kept relatively in check. His later writings became more like opinion pieces, and are constantly self-referential. My irritation with those must have carried over to the original.