That pre-supposes that excellence is the ticket to the award. Which as far as I can tell it isn't. I'm sure that a degree of excellence is a requisite, but you very clearly have to tick several other boxes as well. From my (admittedly rather limited) experience it seem that there's a Hugo type of book, that glad handing at conventions is a big bonus, and that having the approved social messages is another. I'm sure the 'type' changes slowly from year to year and that there are exceptions that have bludgeoned their way through the hoops by sheer popularity and quality but the fact that a couple of authors have won certain categories time and time again (I seriously had never heard of Lois McMaster Bujold before I looked at the Hugos a couple of years back ... and that's a name I _would_ remember) just shouts that it's a clique choosing the clique favorites over and over.
Absolutely. The Hugos are awarded to the most popular books as selected by WorldCon voters, and WorldCon voters have quite specific tendencies as voters. Not all voters, of course, but a significant chunk. Over the past two decades, at least, the "Hugo type" book would be one I'd describe as lighthearted on the surface, but with more serious undertones, and further marked by the kinds of snarky, teleplay-like dialogue found on, say,
Firefly. Scalzi, McGuire and Bujold all fit this mold, so it's no surprise they are perennial nominees.
Nothing wrong with that kind of book (FTR, I quite like Scalzi's
Old Man's War books, and while I didn't really care for the two I read, Bujold's
Vorkosigan Saga is immensely popular for a reason). But I also think voting skews to this one kind of book, and the shortlists routinely ignore other kinds of books--including those that are as or more challenging. And several times in recent years voters have chosen books that are, essentially, in-jokes for specific subsets of fandom (
Among Others,
Redshirts).
But to be honest, I don't think the Hugos are really the interesting bit of the exchange between Wright, Scalzi and others--rather, it's the weird treatment of Heinlein as some kind of stone idol of the lost age to worship and resurrect.