> HackerNews makes it hard to post anonymously. If you signup and try to post a lot of text or god forbid a Show HN you spent weeks building, it shadow bans you for at least five days. It forces you to wait before you can participate.

I don't think that is automatically true, I've seen many new accounts with a single post/comment.

Maybe what happens is that the threshold for your comment to be greyed out is probably lower for new accounts. Same for flagged post, maybe a single flag is enough to kill a submission by a new account?