Quoth Wales:
'Every single person who signed this petition needs to go back to check their premises and think harder about what it means to be honest, factual, truthful. What we won't do is pretend that the work of lunatic charlatans is the equivalent of 'true scientific discourse'. It isn't.'"
It is noteworthy that Wales is not arguing for excluding pseudoscience from Wikipedia on the basis of Wikipedia's own guidelines. According to Wikipedia itself, status as pseudoscience is not a criterion for exclusion from Wikipedia. Rather,the criterion for acceptance is NPOV. Wikipedia's guidelines permit dishonest, fictitious and untruthful content so long as it is NPOV.
Because the rules of Wikipedia would allow the inclusion pseudoscience this is a "gotcha" for Wales, revealing a fundamental limit in Wikipedia: With NPOV, the contents of Wikipedia can never be more veridical than is the social consensus. A purportedly objective guideline which immediately reduces to subjective value judgments, NPOV is a ruse; What constitutes "Significant views," or "reliable sources on a topic" is in the eye of the beholder. Or, as Wales would have it in this case, whatever he says they are.
Wikipedia was an unexpected success because the popular expectation, a priori, was that if you just let anyone edit an encyclopedia then predominantly non-experts would contribute falsehoods. A posteriori, after Wikipedia had actually worked, the reasoning about why it had was that it was unexpectedly accurate because, well, experts are really not so good at getting stuff right anyway, and maybe spontaneous social organization really does work better than structured regulation and those dead Austrian economists and their crazy Libertarian fan club might actually have been right about something.
Though perhaps the secret to Wikipedia's success is not really that open encyclopedias are unexpectedly accurate, but rather that accuracy is not, as had been assumed, paramount. Rather, it is the appearance of accuracy which is essential for success. NPOV is a codification of a strategy for creating the popular appearance of accuracy without achieving genuine accuracy. Wikipedia is winning the encyclopedia contest by gaming the system. It matched the same flawed criterion function for accuracy as used by its customers, the test of asking: "is this what respectable people believe?" So now Wales has the problem that, according to the very rules of Wikipedia which have been the recipe for its success, it must permit pseudoscientific content which is popularly believed. This explains why Wales can shoot that down only outside of Wikipedia's own guidelines.