It has to be flagged enough to get that tag. As to 'commenters are commenting', that's not the criterion for what makes a good post. You're basically trying to stir up a silly fight. Sure, that gets upvotes and comments. It's still bad.
Hm, ok. Would it have been OK if I hadn't posted it under "Ask HN"? Surely this site supports sharing opinions like this one in some contexts -- it's not like this was a political shitpost or something. Right?
Probably but the result would have likely been similar. The standard is supposed to be a bit higher than 'isn't a political shitpost'. If you have something interesting to say about this, you can always write it up as a blog post and submit that. If you just want to vent a bit, it's probably not going to get too far as a post.