Different reviewers have different standards, much like different editors have different standards. There are more potential sources of edits than reviewers however, so the reviewers have to win. There is no system for reviewing the reviewers because that simply gets too meta.  What follows is purely opinion, nothing concrete, but there are a few generalizations that apply here: * **All edits to ancient posts are suspect.** Edits bump a topic back to the front page. The longer it's been since an edit, *particularly if the Q&A has run its course*, the more likely it is that the edit will be rejected. * **Style varies from person to person.** Edits that split hairs on preferences in presentation style are likely to be rejected, particularly when editing an ancient post. Your attempt to segment the answer into headings falls into this category. That was not the only change it was making, but... * **The meat of your edit should not be a comment.** When the iffy parts are pruned away, if the only surviving material would have done well on its own as a comment to the post that is being edited, then it's probably best to lean in the direction of a reject. * **Low rep bias.** The less time you've spent contributing to the site, the less inclined people are to give you leeway with edits they consider borderline. That's just human nature, and not specific to any individual Stack Exchange site.