Mail firstname.lastname@example.org with your reasons. Basically this will need to be handled on a case-by-case basis with human judgement.
The idea is that just because you don't find value in your question any more doesn't mean that it doesn't provide value to other users. If there are upvoted answers, that means that people have found those answers useful - so it would be a shame to remove that useful information from the site.
However, I'm sure this wouldn't stop a moderator from deleting a question where there's a really good reason why it should be deleted anyway. Or the moderator may have other suggestions as to how the value can be preserved while addressing whatever your concern is. For example, if you accidentally included your password in an edit, a moderator (or at least Jeff :) may be able to directly remove that edit or blank out the password.