I really don't think it's right to call android the largest "smartphone platform", because:
1. Really its "mobile platform" and when you look at the post-PC era, tablets, namely the iPad Market is a big chunk of mobil devices, and when you include these numbers- the iPad has really dominant share making iOS the dominant platform. Looking just at "smartphones" is selective reporting to try and exclude the market where Apple has had the most success, skewing the numbers in favor of android.
2. Android is hugely fragmented. iOS devices are mostly all running the latest iOS software and even ones that aren't can all run apps without modification. This is not true on android where covering %80 of the market requires changing your app to support 167!!! different devices.
3. I don't consider android to really be a platform, simply because it is so compromised. As a ripoff of iOS they had to rush it to market and in doing so compromised a lot of functionality.
4. Android is primarily sold to feature phone buyers as if it were a featurephone. These people walk in to get "a phone" and get sold android by the weenies at the carriers store... but they don't use them for apps or for even browsing the web, which is why the web stats on android are so pitiful. Android is really a feature phone operating system (hence the fragmentation and incompatibility)
5. You'd be just as correct to lump all the other Linux derivatives together and claim that there's a "linux smartphone platform".
6. We don't have real hard numbers for shipping devices for android. Amazon doesn't publish actual numbers. Google doesn't publish actual numbers. Samsung doesn't publish actual numbers. There's a lot of hype and BS claims that these devices are selling in huge numbers, but when samsung was forced to report actual sales in the lawsuit last year, it turns out that when journalists were claiming big sales the reality was pitiful. Most of these "sales" are actually non-android featurephones also sold by these companies who don't break them out because they want to seem more dominant than they are.
Get me real numbers reported in annual or quarterly reports that would result in an investigation by the SEC and charges of fraud if they were made up-- and use those.
Apple provides them. Until android manufacturers are willing to report the numbers under penalty of perjury like Apple does, they're just PR smoke, nothing more. (or analysts "projections")
These stats are being distorted by the propaganda of android fans who claim that it is a platform, and a smartphone platform at that and that it is dominant