I do not like it my meta question, Why has my question from October 16, 2019 been downvoted?, has also been closed as opinion based because I asked a meta question about my own question. Why is my meta question closed?
Your meta question is actually not a question. It is a comment that you cannot understand why a main site question of yours was closed. As a result:
- I dunno how your non-question in meta can be answered,
- Even if we understand your meta post as a kind of question, it is not possible to answer it in any way except by formulating a speculative opinion on the reason why your main site question was closed.
- As an aside, my opinion is that asking for people to justify their VTC is bad form. It’s enough to understand that the question needs improvement, or that the answer is readily available (as is the case of your main site question relevant to this discussion).
Your question is not an opinion. On the metas it is widely accepted to start a question about a main site one. (Typically, OP wants to know the reasons of the down/close/delete votes. Or asks for a discussion about the revival.)
Voting up and down is free, thus up/down votes represent opinions (about your main site question). But, what is the typical opinion of the avid voters, that is imho enough objective to survive on a meta.
In my opinion, your meta question should have not been closed.
Your main site question might better match the History of Science & Math site ( https://hsm.stackexchange.com ). There a problem what I can see with it is that the answer is encyclopedic (first hit in any search engine, it is not an interesting question). But possibly the community will decide to remain.