It's always seemed like a sort of dehumanization to me -- IDK about actual hate hate, which may have other causes, but the attitude some men have toward women reminds me of how one might talk about a dog. They can feel affection, love, admiration, and even recognize a woman as better than them in some narrow way within the female domain (there's this weird sort of sexist humblebrag I've seen where men will brag about how their wife is better than them at some female-coded thing and how helpless and bad they are at it, or the whole "my better half" feminine mystique trope of purity and goodness), but it always comes back to seeing them as both apart/different and lesser somehow. You'll see the same attitude crop up among some women toward men on occasion -- that they are a pet to be cared for rather than an equal (watch some daytime TV ads if you want to see examples of this). It's an understandable reaction to being treated thus by men and it sells the household products.
I think the best answer to dehumanization is integration from childhood, though I grant we've mostly had this for some time and the problem persists, and there are good reasons for much of the remaining single-sex environments (bathrooms, sports teams, etc). I'm optimistic it will gradually improve each generation. I also think that parents can play a role by helping encourage their children to perceive boys and girls as primarily the same rather than the other being weird mutant alien creatures from another planet or whatever. Teaching equality isn't enough -- you need to teach them the other gender is people if you want to break them out of a tribalist rut. And dangerhair bullshit, and the reaction to it, makes this harder than it already was.
I really do notice among people my age two very clearly distinct attitudes on gender though -- treating people like people with some differences vs some variant of two different tribes separate but equal. It's always bugged me.
As an aside, I appreciate OP's worldwide perspective on the problem.