I think if the GP had written something relevant about their personal experience in a scientific field, that would have been much more interesting, as well as not breaking the site guidelines.

The trouble with your argument "interesting people don't like censorship" isn't that you're wrong—it's that there are also a lot of people (many more, actually) who post dreck. If you want a forum that doesn't get overrun with internet dreck, you have to have some strategy for countering it. HN's strategy is to have a clear organizing principle (https://hn.algolia.com/?dateRange=all&page=0&prefix=true&sor...) and clear rules to support it (https://news.ycombinator.com/newsguidelines.html). That barely works, but it's a lot better than nothing.

It's the opposite. The moderation is good, is very needed, and helps keeps discussion quality/signal-to-noise high, making this a site worth visiting. The thoughtless flamewars you can find everywhere else on the web are what bore me, personally. The rules of conduct on this site aren't even a high bar, and no one is preventing anyone from being jerks if they want to merely by keeping it outside of this forum.