Just because there are other products with different experiences that skin it doesn’t mean the core product is bad!
It actually means the opposite - the core product has such value and there are so many users, it actually is able to support sizable enough communities of people ‘outside the core’ to justify niche repackagings for them!
Great UX should also mean fast, efficient, and dense with information. Respectful of time, attention, and intelligence. Not making an assumption of stupidity on behalf of your users.
Great UX should primarily mean those things, at least for a certain subset of software.
Making links in profiles and text posts clickable. That's like the most basic thing you can do for your users.
Adding the ability to collapse a massive comment thread without having to scroll to the top. Also, indent guides (especially needed for the massive threads around here). Shit, HN didn't even have collapsible comments for the longest time.
Being able to comment inline and not having to navigate to a separate page where you lose context of the surrounding discussion.
Highlighting new comments since you last viewed a thread.
These are all basic things that HES addresses, there are many more I can point out. I'm not trying to insult the admins, I think they do an amazing job of running the site, but let's not pretend HN is some pinnacle of UX design. We are all just very used to it.
And personally, in the years I’ve been here I’ve never noticed or cared about any of those issues. shrug