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?

I, by stark contrast, am autistic only figuratively.