Earlier quoted context omitted.
Scott absolutely analyses topics in bad faith, particularly when it comes to politics or movements/people he personally supports. Here's one where he essentially says 'no study is ever fully representative, therefore my friends twitter polls are exactly as good evidence as a scientific study': https://www.astralcodexten.com/p/selection-bias-is-a-fact-of...
Your comment is an example of analyzing in bad faith. In the linked article there is a whole section that starts with "Selection bias is disastrous if". He definitely does not says anything remotely close to "twitter polls are exactly as good evidence as a scientific study".
He starts by stating that people say his surveys and Aella's Twitter polls (which he calls surveys) have selection bias, meaning the conclusions don't count.
He then goes on to say (paraphrasing): "people say surveys have selection bias, but don't think real scientific studies have selection bias" and in the next paragraph says "but scientific studies do have selection bias and that's ok." Note that in this section, he is implictly relating scientific studies with his and aellas surveys.
In the section that starts with "selection bias is disasterous if", he gives a narrow view of why and when it's bad: "only if you're doing a poll or census that should include everyone". He neglects to say the ways in which it's bad for literally all science (it's a massive problem in drug RCTs, but he literally uses RCTs as a point for why selection bias isn't so bad later on).
In the next few paragraphs he says that selection bias is fine for correlations, and gives some examples of when scientific studies have selection bias that we accept (I'm not going into details here because the post is long, and I'm on my phone).
So he's said why selection bias is present in science, and that it's only really bad for census's and polls. He then concludes, "hey guys stop saying surveys are bad because selection bias, science is also biased".
In this post he starts by bringing up a critism of Aella's 'research', which she uses data from Twitter polls for. He then implicitly equates surveys and scientific studies, and says "look, science is biased too, so selection bias isn't bad". He then concludes, "so stop saying surveys are a bad because of selection bias".
He might not literally say "twitter polls are exactly as good evidence as a scientific study", but the point of the post was to detract from the valid criticisms against his and Aella's posts that use survey/twitter poll data by saying "science does it too".