I think this sums it up really well, it’s the very patriarchal cultures in which ppl don’t seem to want to move forward where this stuff nearly always happens..
Also, we have one of the few cultures in the UK that doesn’t value education as much as we should. The Indians and Chinese (they used to treat their girls horrifically as well) have a reputation for being amongst the most educated over here and so the mindest amongst the majority of them has changed whilst we have remained quite far behind in terms of educational advancement and ‘enlightenment.’ UK Indians have practised honour killings but in far fewer numbers (even in forced marriage statisitics they fare wayy better than we do). Amongst the English they don’t really have the reputation for being ‘backwards’ that we have 
It’s the poorer and less educated communities (Pakistanis, Kurds etc) who hold onto these barbaric traditions more..