In my view, the reason why the “notallmen” thing pops up is because there is a lack of statistics on “howMANYmen”. At least, I’ve never seen any data that shows the extent of the problem from the male POV.
IOW, we see stats on how many women have experienced “X” in their lives. What the men want to know, I suppose, is the other side of the coin before they align with you or ignore you. In a lifetime, one man with a power dynamic could abuse dozens upon dozens of women; that’s a very different social problem than dozens upon dozens of men abusing one woman in their lifetimes each.
It’s a fair question.