Sony can't ignore iOS, it's too big, especially as iOS users are far bigger spenders when it comes to buying apps and stuff. Android users excel only in pirating software for their phones.
I didn't say that Sony should ignore iOS, just that they needn't focus on that platform, over Android which is increasing becoming the more dominant one considering the number of Android devices sold each year, compared to iOS devices. My point is with Android, Sony levergaes the huge installed bases of handsets provided by many handset manufacturers, including themselves, rather than just Apple whom aside from software and content revenue they have no other shared interest with.
Even microsoft can't misdirect users over to their ecosystem, so how on earth would you expect sony to succeed there? Besides, sony has no actual financial stake in the success of android, they only make android phones because it's open and successful, but they could just as well be making phones running another OS. They're not actually making/marketing the OS itself, so wether they sell software for iOS or android devices is irrelevant. It's the sale itself that counts, not the platform it runs on.
You missed my angle entirely with this. I'm not saying Sony should focus on Android because its good for Android. Rather they should focus on Android because its an OS they use for theri devices, and a software platform upon which they can leverage to sell content on devices they also don't even produce. By doing so they have the chance of entrenching people into that ecosystem, making it easier for them to translate laterally from other handset providers to theirs.
E.g. if Sony's next Xperia looks really appealling and you own a Samsung Galaxy, together with all your paid-for apps and content on your Google Android account, you can change to Sony's new handset relatively seamlessly without losing your investment in the software ecosystem (i.e. all your apps). That's something you cannot do going from iOS to Android, and so by bolstering iOS by focussing apps and service software development on iOS you inadvertently drive iOS consumers further away from you and your hardware.
MS is a different case, because MS have their own interests in their mobile windows platform, which is dwarfed by both Android and iOS. It would be senseless for MS to ignore iOS and Android to try to bolster Win mobile, as WinMo never had a chance in hell of becoming a serious competitor in the first place. The difference between Sony and MS, is Sony makes Android devices, and so anything they do to bolster that ecosystem will directly benefit them in the longrun. Hence it's entirely reasonable to focus on that platform rather than iOS.