I would be happy if they allowed usernames to be changed or accounts to be deleted where the username is just changed to deleted or something and the comment stays.

We rename accounts for HN users all the time. 250 so far this year.

That's good to know! Thanks.

If you have been careful all along, this would help. But it wouldn’t solve the problem where someone has inadvertently added some personal information or hints/links to who they are or where they are. People may also not remember where they posted what that links back to them.

We're always happy to delete or redact identifying information. We don't want anyone to get in trouble from anything they posted to HN. We don't do it by allowing wholesale deletion of account histories, because that would gut the threads the account had participated in, which would be unfair to any commenters who replied, as well as to readers and to the community.

That doesn't mean we don't care about individual users' needs for protection—we care a lot about it, and help people with these requests every day. We just have to do so with sharper tools, and we have a big bag of tricks for taking care of these things. They include renaming accounts, retroactively assigning comments to throwaway accounts, deleting specific posts (especially if they don't have replies), redacting specific info from posts, and more.

I think those scenarios the user should contact HN and ask for removal.

It's difficult because even if someone wrote something they regret, they probably also have things they wrote which prompted really good discussion.