On the "Best Practices" Topic
There are no rules specifically saying that "best practices" questions are not allowed.
The link Why is asking a question on "best practice" a bad thing? is if anything a only a statement that usually questions that mention the words "best practices" are not good questions for stack exchange.
This distinction is specially important in Software Engineering Stack Exchange, as there are some very good questions that can be based on the knowledge and guidance of experienced software engineers that would fall under the category "best practices".
Look no further than the example of variable naming. Criteria for choosing good variable names could be considered a "best practices" but there are many books, experiences and stories that make this a relevant software engineering topic. But even so, "Is this a good variable name?" is not a good question as it is primarily opinion based.
The criteria for a good "best practices" question should perhaps be the ones listed in the don't ask section:
Some subjective questions are allowed, but “subjective” does not mean
“anything goes”. All subjective questions are expected to be
constructive. What does that mean? Constructive subjective questions:
- inspire answers that explain “why” and “how”
- tend to have long, not short, answers
- have a constructive, fair, and impartial tone
- invite sharing experiences over opinions
- insist that opinion be backed up
- with facts and references
- are more than just mindless social fun
Back to your question
Now, is it ok to go out and try to enforce some of these "rules" upon other user, based on your own opinion?
As they are not rules per say, I'd say that no, it is not ok to enforce this kind of thing.
- Now, did the person you mentioned tried to enforce this kind of thing?
I'd also say that no. That person only left a comment link indicating that the question should not be in the site, in their opinion.
- Could that person have better explained the possible downvote and the link?
Perhaps. I personally do not see any problem, but sure... one can always improve the communication. But that leads me to the next question:
- Is the person required to leave a comment when downvoting?
No. See this question and the links in it: Encouraging people to explain downvotes