This has always happened to women. I mean, men do it do men too, but other men counteract that by doing it too. As a cis man I’ve encountered way too many cringe worthy situations from my fellow men.

If you’re never experienced mansplaining you might now actually know what it is about.

You went off the rail when you used “women” and “men” instead of “people”.

I’m not exactly sure which one is more frequent, the behaviour itself or the accusation thereof as thought- and conversation-terminating cliche, but both suck donkey ass. OTOH it’s not some special grand thing in itself, either, it’s plain old failure to relate and communicate.

But one group does it far more often.

With “one group” you presumably mean egocentric people in general, and nothing sexed. Because otherwise: Citation or you’re a sexist. And with “citation” I mean “controlled for perceptive biases”.

Your argument sounds like the “all lives matter” of “black lives matter”.

Plenty of citations for racial bias by US police so no, it really shouldn’t. Side note though: The moment the assclowns came up with “all lives matter” the BLM folks should have jumped on it and used it themselves. It’s a much more powerful message, and impossible to argue against. With the momentum they had they could easily have drowned out the racists.