On the subject of clang

My coworker has been burdened with the task of building our product for Apple devices, which, it turns out, means that he has to use clang instead of gcc. On discovering this I did a couple of laps around the room shouting "EXTERMINATE" but when I settled down I wondered if there was a reason they used this. Is this just apple being hipsters or is there a reason to switch compilers?

>>6
What compiler should I use if my main priority is minimal binary size?

>>7
Couldn't they make a modular compiler where the architecture targets are described by some kind of data file external to the compiler program itself? So the compiler itself only knows how to convert from source to IR, but you could "plug in" different configuration files to tell it how to go from the IR to object code?