As a sorta-reviewer, I've had to shut out almost all self-publishers and indie authors for precisely the reasons Wendig cites in his post. And it's frustrating, because I know there are some lovely authors in that sea, but you can't honestly expect me to give up my time and energy reading mountains of legitimately crap books just to find the gems. A while back, I got crapped on for suggesting this. Now, I'm sure all the poop goodness is hanging out in Mr. Wendig's backyard.
Oh, and I seriously mean there are good SPed books out there. I've read some of them. I've even bought some in recent memory. I just don't buy most of the SPed books out there for the same reason I don't subscribe to every blog I come across.