To understand what makes HN different from other sites, you may want to familiarize yourself with the guidelines: https://news.ycombinator.com/newsguidelines.html
In particular, we try to write comments that are interesting to read. That rules out swipes and one-line dismissals: calling something amateurish, or complaining about downvotes.
HN has a lot to offer as a community, and we started out as a tight-knit group of refugees from sites like Reddit. This place has grown up a lot since then, but those fundamentals were the reason for HN's success.
Your second comment was better than your first -- a substantive dismissal is always preferable. And you can write comments like that if you really want to. I usually find it's more productive to focus on what's cool about a piece. There's usually something.
However if an article is mistaken, that's worth calling out. Some of the best HN comments are refutations. Though you'll want to be certain you're correct, or else you'll get called out yourself. :)
Anyway, I appreciate the environment on HN and the steps users like you take to preserve it.