I think both sides simultaneously have a leg to stand on. In terms of self-conduct, I try to skip past the noise and go for what I think is informative, and if complaining about a dentist's teeth is not informative then I skip past it. In this case I think there's more than enough value to skip past all the noisy complaints.
At the same time I understand there is a part of how human judgment works that cannot help but develop a story on why the dentist has bad teeth, and thus it is an informal burden on a proponent to also be an exemplar of what they say.
That's a really good point, and I agree with you fully. What I do not agree with and am not sure if you agree with either, is that the dentist has bad teeth to begin with. Furthermore if you where to say that 1+1=2, isn't in fact 2 because a dentist with bad teeth said it was then you are simply plain wrong.
Personally I find gwern to produce exemplary content*, and on a page that is really well designed. Which very much might be a matter of taste obviously, but this is very much the type of taste that makes me visit HN frequently, both in terms of aesthetics and content.
I would highly recommend anyone reading this, to have a look at the rest of the content on gwern's webpage.
At the same time I understand there is a part of how human judgment works that cannot help but develop a story on why the dentist has bad teeth, and thus it is an informal burden on a proponent to also be an exemplar of what they say.