I think we're quickly approaching a slippery slope here. Seeing as a username is attached to every post, isn't the user somewhat responsible for every link (s)he posts? It now constitutes part of their reputation. Now, if an editor modifies the post but the username is still attached to the post and their is no indication that it's been edited , is the original poster still responsible for the post? (S)he can turn around and say, "That's not what I posted. I don't want that attached to my submission history. I don't want any karma that's associated with that altered post, whether good or bad."
I rarely get involved in these sorts of discussions, and will continue by remaining neutral on this issue. However you've hit on my pet peeve - the 'slipery slope cliche' and so I cannot remain silent.
All of humankind's decisions lie somewhere on a slippery slope - the nature of being a human is making these kinds of choices. What makes us all so interesting is that we continue to live and function without falling down, and we trust each other to do the same. People really need to come up with stronger arguments without falling back on the 'it's a slippery slope' cliche. Every time I hear that phrase, I just want to reply with some other brilliant argument-ender like "now you're just comparing apples to oranges" or "that sounds like something Hitler would have said."
We may be on a slippery slope, but we're not quickly approaching one. Editors have fixed titles from day 1.
I think the best plan is just to make it policy that submission titles have a different status from comments. They have to, because all the users have to share the same title for each link.
Probably the best solution is to have a "posted by" (editor name) and a "submitted by" (user name) like Slashdot. Alternatively, an "edited by" tag added to anything changed after submission.
He may have meant that different users should give a specific submission the same title, one without spelling mistakes and bias. So if a user titles a submission with spelling mistakes or bias then it would be reasonable to edit the title to the correct form.