For the sake of access to women?
It seems they´re really stuck between staying as ethnically Chinese as possible, or admitting that to maintain their national coherence they´ve they´ve got to mate with ¨mongrels¨.
It sucks as a society to have no source, nor even any sense of transcendent values.
Not explicitly for the sake of access to women, but for grandiose, breathtaking, adventure that takes some of the “extra” young men’s attention away from their own lack of access to women, I’d guess. They won’t be out raiding for female slaves to drag back home, but their government will likely try to distract them with heroic, masculine enterprise that’s almost as satisfying as doing the sex to a woman body.