On the one hand, mobile is a (weirdly) huge business.Its huge, but building a store isn't easy or cheap. Releasing the content and apps they have on the Google/app store might just be more profitable.
On the other hand, as everyone points out; it doesn't seem particularly feasible.
Yes, they lose 30% of the revenue to apple/google, but overall it might he cheaper, more profitable and quicker to go down that route.