If a person answers a question in a more or less legit manner and then goes on to write a blog post three times longer than the original answer. Should we consider that "Not An Answer" entirely until they edit it out themselves or do we just remove the extra stuff?
There is strong precedent on Stack Exchange sites for removing material that does not directly deal with the question. One specific subset of such material is addressed on Meta Stack Exchange: Should 'Hi', 'thanks', taglines, and salutations be removed from posts?
Similar rationale applies here. In short, by focusing on answers, and not random commentary, the information on our site is more useful to future readers. Briefly:
- Excerpts of our posts appear in search engine results. If the text that is chosen to appear in Google search results, for example, happens to be some user's diatribe, and not an answer to the question, potential readers will skip over us.
- Text that doesn't answer the question must still be digested in some way by readers. This wastes their time and gives them an incorrect impression of what we offer here: answers to questions.
For these reasons, answers that veer off on extraneous tangents that do nothing to address the question itself are subject to downvotes, edits, and in extreme cases, deletion. Authors do often need some leeway to provide helpful background or explain relevant side issues, but these should still be good-faith efforts to deal with the question itself, not use the site as a soapbox.
Short version: Just because you technically "answer the question" doesn't give you a free pass to write whatever you want in the rest of the post. This is a Q&A site, not a forum or your blog.
I'm wary of a sweeping site policy that encourages users and mods to remove large portions of answers, despite how off-topic they are. This happens a lot on Skeptics and it really quite irks me. To be fair, it's a very different topic with different site rules, but the hard line rules they do have lead to heavy deletion, of which this line-item deletion principle is a compromise. What I don't want to see is such a policy here spiraling out of control where it's no longer clearly nonsense or rudeness removed from answers, but subjective "not related, not helpful, not valid" sort of material (as I believe does happen on Skeptics). In my opinion, that is stealing from the rest of the community. First, post content belongs to all users. Second, if one of us doesn't think it's related, helpful, or valid, we can vote accordingly.
In my personal use of SE and this site in particular, I strongly advise users to remove the extra crap. If it's especially bad, such as rudeness or nonsense, I downvote. I let them know this too. I tell them exactly, "I'm giving you a downvote because of all the extra crap you put in this answer. Get rid of that garbage and leave the good stuff, and I'll give you an upvote." I've seen them change it about a third of the time.
I have simply flagged and downvoted correct answers because they are delivered with hate and spite. I have no patience for sanctimonious jerks. Being right is no longer the point if you can't be polite. In such instances, I favor full post deletion. Such users need an attitude adjustment, not simple site policy direction.
And so I have this synthesis in my mind: If it's a matter for voting, leave it in the post. If it's a matter of moderation, remove it. Lets make sure that we keep this distinction.