The person taking offense was member of C# language design team mind you. There are several such cases. This was particular question I stumbled upon because I wondered the same question and wanted to know what were the reasons. This was perfect Lucky Ten Thousand [2] moment for him if he wanted.
[1] https://stackoverflow.com/questions/59193144/why-is-c8s-swit... [2] https://xkcd.com/1053/
> "Why not?" questions are vague and hard to answer satisfactorily. The unsatisfactory answer is: did you personally do the work to add this feature to the language? The language is open-source, you want the feature, so why have you not done it yet? Seriously, why not? You've asked a why not question, and you should be able to answer it yourself. Now ask every other person in the world why they did not add the feature either, and then you will know why the feature was not added. Features do not appear magically and then need a reason to remove them!
> Moreover, you say that the feature is simple and fits well, so it should be straightforward and simple for you do to the work, right? Send the team a PR!
It's a paradox of poor communication that you cannot prove with certainty that there is an intent behind it. There is always the argument that the receiver should have known better (and bother checking local news at Alpha Centauri).
It is explicitly understood to be doing a favour to the OP: an already-existing answer to a common question is provided instantly.
What would be the harm in pointing out previous answers but leaving the question open to further contributions? If the previous answer really is adequate, it won't attract further responses. If it's not, well, now its shortcomings can be addressed.
Closing duplicates makes as much sense as aggressive deletionism on Wikipedia. It generally means that somebody missed their true calling on an HOA board somewhere.