It actually doesn’t matter if it’s not a compliment. Complimenting a stranger (or asking them out) isn’t harassment in and of itself. It can become harassment, if you for instance tell him to leave you alone and he doesn’t, but I get the impression this qualification is not met in many cases where women talk about harassment. What seems likely here is a kind of prejudice, where past experience or second hand stories / media has taught women to treat men and sexuality as threatening prima facie — this is exactly as sexist as it is racist to treat black people who approach you as threats for no other reason. Calling behavior harassment that isn’t is a kind of unwarranted and sexist discrimination. But for what it’s worth, calling out this behavior as a nuisance and a bad idea seems admissible. Certainly from a man’s perspective, this is just so clearly a terrible strategy to attract women, and in every respect counterproductive. That’s largely the only kind of message men who approach women in public will be receptive to anyway, as they rightly perceive women do not have the right to not be hit on — in fact, if women did hold this right, it’s hard to see how the dating market could even function in the first place.