I agree with you that sometimes downvoting can come across as pretty irrational/emotional, and like any community HN has its echo chamber qualities. However in

I agree with you that sometimes downvoting can come across as pretty irrational/emotional, and like any community HN has its echo chamber qualities. However in my time here I'd say that's the exception, not the rule. The majority is actually pretty fair. Side note, if you want my 2 cents, I'd guess the reason why your comment on the System76 laptop was downvoted is because you said "X is just better than Y" with minimal evidence and you didn't present it as an opinion. If your comment said something like "My opinion is..." or "Anecdotally" I think you likely would have gotten voted up instead. Don't take it personally, the community here tends to be very focused on hard evidence or being clear about an opinion being that.