Why do films sometimes have different names in different parts of the English speaking world?

The explanation is simply that the title of the film is the same as the book it’s based upon, but then one can wonder why the publisher (translator?) chose to change it.

Because “Men Who Hate Women” sounds like a self-help book. Specifically, Men Who Hate Women (And the Women Who Love Them) – actually a very famous US self-help book.

I agree that “Men Who Hate Women” sounds too much like a drama movie instead of a detective story.
“Men Who Hate Women” sounds like something you might watch on Lifetime.