To an extent, this is true, but take it too far and you begin dismissing education and well grounded logic and believing it to be equivalent to ignorant and irrational thought. Logical thinking and analysis is a skill you learn and get better at after all.

The trick (which is very hard) is to recognise when one of your own arguments is one of convenience, emotion, illogical etc. And not be biased towards logical fallacies against others.

But this does not mean that your average person on hacker news doesn't tend towards better educated and more rational discussion than large amounts of the public. It also means hacker news tends towards specific blindspots, sure.