As Apple is taking a LOT of Flak right now for its iOS 6 map application, I suspect there will be other options soon. Either Apple or some third party will have to address this and many other issues. I personally find the new "Map App" to be vastly inferior, as it is now.
While in general I tend to be an Apple Advocate, one of the things I dislike about Apple, is a general trend (in both marketing and design) to assume people who live in rural areas are of no importance. This could get even uglier as Apple moves into mapping... I hope they prove me wrong.
Well, we have no idea about the why. Did Google ask for more money or deny to give license? Did Apple decide to get independent to avoid being susceptible to blackmail?
No idea, so enjoy Flyover :-)
I think some of the "Why" is likely related to the ongoing legal battle between Apple and Google.