I don't totally agree with you that reason cited for closure of the question was completely inappropriate. I would agree however that there could have been a better reason cited. Regardless, it was very definitely a "low quality post". To some, it may have been unclear exactly what the user was asking or wanted to learn from the answer to his question.
I see that I happened to be one of those who voted for it's closure. As I read the question now, it definitely wasn't phrased in a way that provided sufficient context to give anyone who answered it the information to know exactly what he was trying to learn. I can't say if this was a matter of english being a 2nd language, one of grammar, or related to the user's writing ability.
As I'm certain you know, but for the benefit of those who don't, very often the reason cited for closing a post aren't a unanimous decision. Some who voted on the question may have voted it as being too broad or may have voted to close the question for not having code to reproduce a specific problem. The latter reason perhaps being related to it being a low quality question where it could have been interpreted as the user needing to write a trigger to satisfy a need that wasn't disclosed in the question.
Again, the latter points to a question that was of low quality, open to interpretation and not totally clear what he wanted to learn through asking the question. To me, it was a question that showed the user hadn't spent time going through Trailhead, the Apex Workbook, the Apex Developer Guide or other fundamental documentation/training that's considered a pre-requisite for developing on this platform when writing Apex code.
This isn't a place that's well suited to providing in depth, blog length answers to poorly constructed questions on the fundamentals; particularly those that a user needs to study in the docs and tutorials where the material is already well covered in numerous places throughout our ecosphere.