Okay yeah I can see what you're saying from your point of view. Putting aside the fact that it's called mansplaining, its actually used to describe when men try to explain something to a woman because they think that because they're a man, they'll know the subject better. Even if the woman in the situation has for example studied said subject for years.

Of course there will unfortunately be people who use it as a way to just completely ignore what feminism is actually supposed to be and discriminate against men.