I suppose they just need more and iPhones fall short of their needs.
Maybe, just maybe, Chinese people don't see much value in belonging to a cult with western roots, perhaps being a member of that cult does not mean much to them. Perhaps the Chinese value bang for the buck more than those in the cult do.
Yes I know, for those in the cult something like that may sound inconceivable, preposterous even, but you know there are all kinds of people out there, even weirdos who don't crave, or even care about apple stuff, they do exist. REALLY!!!