I think this comment is spot on. MS is a loooong way from losing the enterprise, but that isn't where the money (or growth as you pointed out) is anymore. They really have nothing to lose from going open, so they're best bet is to get in bed everywhere they can so they have a position to work from later if they happen to develop some advantage.

Apple is killing it on all fronts it competes on, but I wonder, will people continue to pay $800 for a new phone every 2 years, $2500 for a new laptop every 3 years? My intuition says no, but from what I read, Apple is taking more and more market share where it matters, in 1st world countries where there are actually profits to be had. I used to slag on iOs because it was so limited and primitive, but the reality is, they're probably strategically releasing features when they choose to, it's not like they're not smart enough to figure it out. If they're lazy, they could just let Google do all the expensive proving out of features, and then release a better version constantly a year behind and make a killing. Kind of like what Microsoft did for so long, except Apple has much higher volumes.