I recently started reviewing edits that others make to questions and ran into the following situation a few times:
Joe adds a question to Stack Overflow that is poorly written.
Mike comes and edits the question and makes some helpful edits, but also adds things that might be comments or even an answer in the question text.
Gary comes to review Mike's edit and doesn't want to reject it, because there are valid parts of Mike's edit that should be kept, and because he'd lose Mike's answer or valid comments. Gary can't "improve" Mike's answer, because he can't move parts to comments or answers as if they had been made by Mike (to make those new comments or answers look as if they were written by Mike vs. Gary). Gary would then go to the reject screen but see that it only offers him a handful of textareas in which to describe the issues vs. a way to selectively approve or mark-up the edit that needed help.
I would like to avoid downvoting and rejection of edits because they can be interpreted badly by the person that it affects. Has it been considered to be able to "mark-up" rejections so that the user that submitted the edit that got rejected can see what they did right as well as what they did wrong, and be able to easily just correct the things they did wrong? (i.e. implement a more helpful but more complex edit rejection interface.)
I know that would be more complex, but just a simple rejection of an edit with a comment is sometimes not the best course of action it would seem. Why am I wrong?