Huck, if we couldn't delete posts entirely, the alternative would be "Comments deleted by APSmember342." You would rather see that just so you know who posted when? How much would that help? When you miss a post that's been edited, you just miss it. Threads move on. Not much of a solution, unless you ditch editing entirely. How much of a problem is it, though?
In real life, if you said something, you cannot un-say it.
Deleting or editing a post isn't unsaying anything, especially if it's quoted. And if it's worth deleting, it will probably be quoted. Deleting a comment is like going out and collecting every copy of your own book and burning it. You may destroy the primary source, but those who read it remember it and can quote you.
What I have asked, if poorly, is a question of what liberties are available here, how they are used (and abused?) and whether this particular function is a good thing.
Fortunately, those questions were answered in some detail by very knowledgable and articulate people. Unfortunately, they all deleted their posts.