We generally tell people we're banning them and why, but there are two major exceptions: spammers and serial trolls. By serial troll I mean someone who we banned at least once already and who shows up again and again with new accounts to break the site guidelines, knowing perfectly well what they're doing. When people do that, it no longer makes sense to post a "we're banning you" comment every time—they've already made quite clear that they don't want to use HN as intended. Your account, if I'm not mistaken, is very much in the latter category. In fact, if I'm not mistaken, you've done it dozens of times by now. That's why we shadowban the new ones.
None of this is new (https://hn.algolia.com/?dateRange=all&page=0&prefix=true&que...), and you guys aren't likely to get very far with the community about this.