The post does not answer the question.
As a matter of fact, it doesn't even claim to answer the question, it even clams to "go beyond the scope of the question" and offer a "supporting diagram to the question". It does not postulate an answer to the question that was asked.
The post was not inherently "bad content" or anything like that. If this was a discussion forum it would have been a perfectly acceptable post on the thread. But this is not a discussion forum and you should not expect posts to be treated like replies would be in a forum thread.
It is the job of moderators to remove posts that are not answers.
As a matter of fact, this job falls to more than just moderators. All site users have access to a link to flag posts as "Not An Answer", and all high-rep site users are shown such flagged posts in a review queue and have the ability to vote to delete such posts.
The only thing special about moderators is that our votes on those actions (such as Vote-To-Delete) are binding. It takes a couple separate users voting to delete to actually remove a post, one moderator can speed the operation along with a binding vote.
The help section spells out the details. of user and moderator action types and specifically about post deletion.
The post was flagged as NAA (Not An Answer).
- ...by a user other than myself.
- I agreed with the assessment.
- ...and acted accordingly.
- Since then a third voice has agreed it was NAA.
The post was deleted fully in accordance with this site's modus operandi and I believe I'm doing my job as a moderator.
What you should do...
If you (or anyone else) see content posted as an answer that does not directly answer the original question you should ⓐ flag it as NAA and ⓑ vote to delete if you have that option and ⓒ if there is content that adds value in the way of background information to the question or other answers, that information can be edited into the respective posts. If it helps frame the question better, edit it into the question. If it helps support another answer, edit it into that answer.
- Expect answer posts to answer the question.
- Expect non-answer posts to be removed.
- Use the site tools accordingly.