Saying that there's one solution that's clearly superior to others show a profound lack of understanding. The MSP430 LaunchPad you speak of may cost only $4.30, but there is a price --- very small amount of RAM (512 bytes) for the Valueline.
While the Android phones are good platform if you need all the fancy hardware and touch screen, they are lousy if you have to deploy more than one or two, price-wise. On the other hand, if you need some of the features that are already available on Android (or, STM32, for example) for much lower price, it would make little sense to add those features (Ethernet or wifi, for example) to Arduino unless you have legitimate reasons.
It all depends on what your target applications, man.