Yes indeed, it's a place for constructive conversation.
There's no problem with humour in your comment but that shouldn't be the point of your comment (at least IMO).
Before anything else read the guidelines, they're short, easy to understand (IMO) and practical.
It's never a game for points.
Before voting on an article (link) make sure you've read enough of the article to actually place value (or lack there of) in it, again it's not a game for points.
If someone is rude, overly negative towards someone else without being constructive it's totally within anyone's rights to politely refer them to the guidelines.
Practise empath and respect for others regardless of their personal opinions (as long as they are framed as opinions!).
Learn from anything you were wrong / mistaken about and better yet - share what you learnt and how you discovered you were mistaken with others, that can really help communities prosper.
Tldr; Read the guidelines, if you're going to be critical - be constructive (which is a great thing!), learn and share with others not for points, but for the greater good and practise empathy.
