I don't have a horse in the "is nicotine good/bad" race, but having lots of references and being argued to death isn't a proxy for being true. Gwern is a former wikipedia admin so peppering everything with references and going line by line, usenet style, to demolish someone's argument is his bread and butter. That just makes him an excellent rhetorician in the online community of people who relate to this argumentative style (typically people who read wikipedia a lot), not a source of truth. When it comes to fields I know a bit more about it's pretty easy to see through the irrelevant citation gish gallop.