How I know about the penalty? I spotted a 3 points submission today on the front page. This one https://news.ycombinator.com/item?id=22171271 right now is on the main feed (3rd page), with only 3 points. This one here had to wait for its 5th point. (Or was it a time based penalty?)
I understand the need for moderation, but such false positives are most frustrating. Though I suspect by now that the real problem is the sheer popularity of HN. Too many eyeballs attract too many submissions, it's become like spam filtering.