This article definitely has a political subtext. Spoken Cantonese and mandarin are mutually unintelligible, but in written form, at least without colloquialisms, they are basically the same language. I'm a non-chinese that studied Chinese, so I have no horse in this race. I do think they should support the Cantonese input method, but there's no reason the pinyin method wouldn't work just as well, other than lack of familiarity. I'm sure Apple is excluding it at the behest of the mainland government, which sucks, but just this isn't as cut and dried as the article makes it.