You're assuming that we read everything that gets posted here. That's far from the case—there's far too much—so it's a non sequitur to conclude that if a bad comment shows up unmoderated, moderators are somehow allowing it. The likeliest explanation is that we didn't see it. Software can do some things, but I don't know how to write software that determines whether comments are right or wrong and kills the wrong ones. Do you?
On a large, open internet forum like HN, any banned user can create a new account and walk back in through the front door in 30 seconds—and many do. There will always be plenty of bad stuff getting posted. We do as much as we can, but we rely on users to flag comments and/or email us in egregious cases. As far as I can tell, you've never done either of those things, so I'm not really feeling your good faith here.
If the game is to find one shitty unflagged comment and pass it around as proof of moderator malfeasance, that's not a very interesting game. What's more interesting is that you had to go back over a year to find it. If anything, that rather suggests that your example is evidence of how little of that there is on HN, relative to other large open forums.
Meanwhile there are numerous cases of you treating others aggressively and being, frankly, an asshole on this site. You euphemize that as "impoliteness", but it's worse than mere impoliteness. It is community-poisoning. "I would take impoliteness over toxic ideology" is a non-argument—there is no good reason to have either. Using one to justify the other is bogus, and using it to justify your own mistreatment of others is cheap.
If you sincerely want to participate in the community here and do what you can to make it better—by following the guidelines, treating fellow community members respectfully, flagging egregious comments, and so on—that's great. You are welcome. But if you really don't want to do that, please don't post here. In particular, please don't take wrong comments by others—or comments that you feel are wrong—as an excuse to vent aggression.