Hi Terje,
for one, there have been too many phones becoming incompatible with newer (minor) versions of Android. I appreciate a longer maintenance of my device and the OS. Secondly, I'd like to support the innovator, which to me is Apple. Should they continue to innovate, I'll be supporting them. Thirdly, to me Android is the attempt of simply copying what Apple had imagined and created. Lastly, the iPhone and iOS are so perfectly suited and made for each other, that the user experience is simply superior. Very lastly, the price differences between iPhone (which I think is superior), and the latest Samsung and HTC phone is so marginal, it's not even tempting anymore from a cost perspective.
That's how I look at it.
Oh, and as a nice side effect, it just interacts seamlessly with my other Apple infrastructure, so again, no pain and struggle here either ;-)
Cheers,
Frank