Ad hominem. If instead of saying "X is an idiot, anyone can tell " you'd say what's wrong with his argument, you wouldn't look like a talking head.
Danny Sullivan does not actively "do SEO" anymore, a field that changes monthly. He reports on news that other people discover about happenings of the search engine industry.
Hence why he concluded that he didn't know what happened to MetaFilter. Because he has no fucking clue how modern SEO works anymore.
And it's dchuk.
In all seriousness, it would be more helpful if you'd mention what's wrong with the original article.
Since you seem to be knowledgeable and active on the SEO front, would you mind explaining what happened to MetaFilter?
We have omnipresent and omniscient Google (or so they think) with high priest Matt Cutts bringing the tablets down from the mountaintop.
The SEO crew are on the ground busy reading chicken entrails and tea leaves and coming up with the best guesses they can but they really don't know.