There is very good reason for Apple (contrary to many other luxury brands):
It's called the network effect: The more people use an iPhone, the more valuable their iOS platform becomes.
FaceTime, iMessage and Photostream sharing are rather pointless, if others aren't on iOS. A higher number of iPhone users attracts 3rd party developers and means a bigger, more competitive market (ultimately providing better products), ultimately leading to better pro. Also, modern smartphones are a somewhat complex devices - many people will be shying away from buying into one platform if they are few users in their peer group or amongst their relatives.
Just look at Microsoft: I think that with WP8 they have a very attractive and promising platform on their hands: elegant modern looks, easy to use, social network integration, good if not great hardware options at attractive prices. In many aspects I'd consider more appealing than Android. In some more than iOS (at least for personal use, hardly for business use). Yet their market share (and mind share) is minuscule compared to Android's.