Yes you can clearly see the contrast between that thread and this one, starting from the root comments, and that's the point: it's possible to have a factual discussion, and it's possible to start a massive flamewar with exactly the same underlying facts. The burden is on commenters to contribute in ways that are likely to lead to the former, not the latter. Of course you can't know for sure what the effects will be, but you can play the odds. These things are fairly predictable.

(Btw, I've partly answered your other questions in a different comment: https://news.ycombinator.com/item?id=27776445)

Here are some principles that have emerged over the years here, as supports for the kind of discussion we're hoping for:

"Comments should get more thoughtful and substantive, not less, as a topic gets more divisive." - https://news.ycombinator.com/newsguidelines.html

Intent doesn't communicate itself on the internet, so the burden is on the commenter to disambiguate. - https://hn.algolia.com/?dateRange=all&page=0&prefix=false&so...

The value of a comment is the expected value of the subthread it forms the root of. - https://hn.algolia.com/?dateRange=all&page=0&prefix=true&sor...

Trolling can only be measured by effects, not intent. - https://hn.algolia.com/?dateRange=all&page=0&prefix=true&sor...

Scorched earth is not interesting. - https://hn.algolia.com/?dateRange=all&page=0&prefix=false&qu...