Humans like to talk, so if we don't have anything to say about one topic, we'll change it to what we do have something to say about. All we need is a path of associations from A to B. The way to get there is first to switch to a generic superset of the topic (Paris Syndrome -> Paris), i.e. go to Central Station, and from there hop on a train to something you have opinions/feelings about (Paris -> Dirty streets in Paris). In this case the path was also plausible because the OP references tourism. But at least the comments here are talking from personal experience, rather than going into generic ideology, which is worse (and did flare up in a spot or two).

Hopping to more generic subjects makes threads less interesting, because the larger a topic is, the fewer unpredictable things there are to say about it. Even if one comment manages to say something unpredictable, the replies quickly revert to predictable things. The most-commonly-repeated arguments have accrued so much mass that no discussion can resist their pull. Therefore, one rule that has developed on HN over the years is to resist generic tangents: they are antithetical to curiosity. Curiosity likes to look around and see something new and specific; generic tangents are powered by emotional energy that wants to talk about something old and familiar.

https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...

Edit: This is a medium-is-the-message thing. A large, flat, open forum like HN can't discuss generic topics well, because of the mass effect I mentioned above. For such discussions to be interesting requires longer (for depth) and more individual (to stay on track) genres. An essay at least, if not a book.