I would be a little careful assuming that just because developers can develop for all platforms at one time, that is the only outcome. Certain applications will only work best on a Mac or only work best on mobile. The ability to develop once is great where it makes sense - think about websites that operate both on mobile and on full-size screens with keyboards and mice. However, forcing everything into that model is shoehorning the impossible, and that's more akin to Microsoft’s problem.Yeah, that worked out really well for Microsoft. Especially their mobile products. The more I see, the more the current Apple looks like the old Microsoft. Feh.