He used it as an opportunity to (to my mind) criticise self-published indie authors. These are writers who write for love, not glory, and just want people to enjoy their stories. Many are given away free. These people cannot afford an editor and yes, mistakes will creep in. I mean, I've seen mistakes in books published by large publishing houses - they happen! He said the writing was not of a good enough standard - whether he got to fairly test this or not I can't say as there were a lot of books for him to read in a short period of time.
The 'winners' were (3 out of 5) published by independent publishers, not self published and so benefitted from editorial support, art, formatting and limited promotion. Of course, the standard of these is going to be higher, they have a team around them to make it so.
He claimed only these five books out of eight hundred had any merit. I wonder how he found time to read even the openings to eight hundred books in a matter of weeks.
I don't begrudge these winners, but I am disappointed this was not the opportunity for the unknown writers out there that it purported to be. I'm sure for The Guardian and Mr Walter it was great publicity though as the sci-fi community is huge.
To all the truly indie authors out there - keep going and the audience that appreciates you will find you.