One of the reasons this sub exists is to discuss possible causes of MEs which can include misremembering, wrong information, common misconceptions etc. That's part of the discussion.

You say, "You can’t just say that people are wrong. They know it’s “wrong” but they’ve only just found out. They’ve always thought it was something else. That’s why they are posting it here." The question then arises, why does OP remember something contrary to what is currently known? To use your wording, why are they "wrong", what causes them to be "wrong"? That's why people try to "explain it away".

You stated:

"Saying that the person is just dumb, >misinformed, or that something is a common >misconception, or that it’s common to think >the thing happened because something >similar happened..... doesn’t disprove a >Mandela effect. It means you didn’t >personally experience it. It’s not your timeline, >your simulation or whatever is causing this >didn’t affect you."
You also said: "If it’s not a Mandela effect for you that’s cool. >It might be for others...".

This makes it so relative that it walls everyone off from each other. It implies that since people have different experiences, they can't discuss their experiences. Yes, some are affected while others are not, but we can still discuss the causes.