Your question was closed per the comments on it. The closure has been explained. The question is loaded, the premise as stated is wrong, and you know it.
Speaking of the comments, it only got closed by one mod after an extended discussion between yourself and a different mod, so the closure wasn't exactly unilateral or unexpected. (And of course mods can't help their close votes being unilateral, that's by design.) In the course of that discussion you did try to improve the question, which we do acknowledge as something most people never even bother with. You just didn't quite get there, is all.
You are certain that it should be who, and have consulted a number of places that all confirmed it should be who, but you still go ahead and ask, "I don't apprehend why whom is correct". All we can do at that point is repeat right back "well, it is not". Which people did, in comments and an answer alike. So there's little point in keeping the question open in its current form.
Canonical questions exist precisely so that we don't have to have a dedicated question for every single typo in the history of mankind. More to the point, we cannot explain the reasoning behind every single typo (or whether it is indeed a typo, hypercorrection, a brain fart, an OCR bug, or plain incompetence). Only the author will know. Perhaps not even him.
With all that said, the duplicate close reason is a very soft one. The softest of them all. It basically says two things:
- Whether or not your question is closed, it will stick around forever. So you lose nothing.
- Whether or not your question is closed, you are unlikely to receive insight apart from that which has already been supplied. So again, you lose nothing.
You are welcome to edit your question to be substantially different, though if you already got an answer to your original question — which you did —, you are best advised to post that different question from scratch, because otherwise you'd be doing a disservice to the person who answered your original question and whose answer will no longer match the edited version. (If it still does, then the edit is arguably not substantial by definition.)