Maybe because it's not an argument, but a series of observations.
I completely agree with the blogger's underlying point that the bar for literature has been lowered and lowered until Amazon (and Apple, et al) finally came along and snapped it in half.
Now everyone and anyone can "publish" and the sluice gates are wide open. And most of what we're being flooded with is the crap that had been mercifully held back.
I think this blogger is conveniently overlooking the publishing industry's role in this mess, though. They're just as guilty as the egomaniacal hacks with more money (or schmoozing skill) than talent. This person buys mediocre yet salable manuscripts while rejecting true art, because big publishers are in the business of making money, not fostering art. Self-publishers didn't start the commodification of books--they're just capitalizing on it. The reason there are too many books being published and yet too few great manuscripts coming down the pipe is
because the publishing industry is just that--an industry, struggling to generate profit in a free market system.
If this person worked for a small indie press with cachet I'd be more sympathetic, but as far as I'm concerned this is kind of like a rat whining about the cockroach problem. I mean, yeah, their points are on the mark--but so are some of the SP zealots' points about the shittiness of trad pub.
I do find it kind of amusing that the idea of writers just wanting to be read seems so strange to this blogger:
Many writers, it seems, care only about having an adoring reading public. If that means they have to pay their own money to get published, and then give their work away in the hopes that by some miracle they'll end up on the best-seller list, then so be it.
The "pay[ing] their own money to get published" bit is, of course, troubling...but is it really so bizarre that most writers write for the joy of being read?