A lot of people have been taught, from a young age, and in school, that there are no substantive differences between the moral values of differernt cultures.
Usually not consistently, since they are also taught that western culture is uniquely bad, but I think they are actively discouraged from thinking about the possibility that any culture may have some really bad or exploitative beliefs. And it's really hard to change that habit or even recognize the assumption behind it.
But also, I think some strands of feminist discourse discourage that kind of realization, because of the insistence that western culture is so bad and rapey, the idea that it's fully committed to keeping down women and does nothing to mitigate those tendencies in men.
I think that's largely untrue, and our culture has actually done a lot to make those views unacceptable and shape men to restrain that kind of thing and to respect women. Enough so that it compares pretty well to cultures that don't do that. But if your assumption is that society in the UK is ok with rape etc, maybe it's hard to realize that some other cultures may be even more ok with that kind of thing,