A few minutes ago BlackBerry announced BlackBerry Messenger (BBM) for iOS. With that announcement, every single one of Apple’s major mobile competitors now makes apps for iOS.
Follow the money: Apple makes it on hardware, so there is precisely zero benefit to supporting other platforms. Google and Microsoft, on the other hand, make money through advertising, software and services; serving iOS users is simply a way to increase their addressable market.
What this says about Blackberry is more interesting: apparently they’re no longer a hardware company with services, but a services company with hardware.