Indeed, and after seeing the comment to that effect, I realized how much superior that proposal was. Everyone is happy -- comments stay put, no insane hand-work is required, and there's no tracking the person to their old content.

In rethinking about it again due to your comment, I agree that there's no way I could mean what I said with respect to someone (like yourself) with a huuuge amount of content. For someone who made an "oops" and posted some stuff without thinking about a good user name, perhaps it was a reasonsable suggestion.

I didn't think through all of the situations in which someone would want to remove an account, and should have done so.

The suggestion for a simple change of username is wonderful.