Not only has he limited himself to Android (you notice no other mobile platforms in your list there) he's chosen to take an exclusivity deal from Sony so that it's artificially limited to only the Xperia Play for at least a month or two.
Android is Java based ... Minecraft is java based ... seems only logical Android is first. I don't really see it going to any other OS myself... maybe the Win7 phone when the xbox version is completed. I bet that payment from Sony was to convert it, I doubt they had plans to ship to xperia otherwise. If it sells as well as the PSP it will hardly be marginal.
And one to two month is hardly exclusive, its just a marketing gamble by Sony.
You seem way off point with your analysis. Seems they are actively moving across every major platform.