I have asked some questions about why a specific programming language does not have a specific feature. They seem to have unpredictable/mixed reception as they are sometimes but not always closed as lacking focus or opinion-based.
I do not see how they are unfocused if they focus on one feature on one language. There are specific reasons why a feature was chosen to not be left out in a certain language. I could see how Why do many languages not support named parameters? gets closed because the question does not focus on one language only and thus invites list-style answers for any number general reasons not to add the feature. But if the question focuses on one language only then the reasons are limited to those specific to the language.
Our community does not always vote in a coherent manner, and I cannot read the minds of those other voters. Often, votes may depend on who is online at a specific time and reads your question. Votes on your question can also depend on the answers it got within a certain time frame. What I can do is tell you my thoughts:
When I read your question about Java arrays first, I saw the problematic issues mentioned by Eric Lippert. It seems, in between, you edited the question to adress these problems and focussed on "what prevents" instead of "why not". After that, I voted for undeletion and reopening. Still, it is sometimes hard to get a deleted question reopened because of the restricted visibility of deleted questions. I recommend to flag your question for moderator attention, since I think it deserves a 2nd chance (but don't be disappointed if that does not work, there is no guarantee).
The question about C arrays got a nice answer within an hour after you asked it. This answer showed that - though questions about "why certain language feature does not exist" are often problematic - this specific case is answerable. Maybe that was the reason why it was received much better by the community.