Of course I may be just projecting what I do, and anyway this response is largely driven by my need to think.
Your post fell into the form of argument because that's sort of what the internet trains us to do. It's the path of least resistance when we want an excuse to write another post after the one we are currently writing. It's the primary game of internet fora.
One of the observations of 'dang and PG before him was that a problem which is particularly salient in political threads is people arguing rabidly when they agree...and those 'arguments' turning heated and nasty. In other words the comments devolve to look like the rest of the internet. That's sort of the reason why the Idea thread was problematic: the conversation could have been happening anywhere. There were none of the elements that make HN HN.
And that's just what I used the opportunity provided by the reply button under your post to write because I felt like writing, i.e. I was just indulging my thinking habit...and working to improve my writing in more or less a free writing exercise with writing as the topic.