Better support, longlivelity, if he decides to buy more apple products they work awesome when paired together. Hard to f something up as iOS is closed system and hard to mess it up.
And when he decides to upgrade he'd sell it for not much less than he paid for it.

I convinced my friends to switch to an iPhone and they all are so grateful, additionaly we're able to use shared albums and so on (i belive such thing is also on android).