So there was a real technical need. IIRC, there was also a personal need, as Steve wanted to do something else, and I am sure not being dependent on gcc was also a big deal.
From long experience, Apple doesn't like to be dependent on others for crucial bits of their tech stack. Relations with the gcc team weren't the best, even without the GPL issues, although the new GPL v3 was also seen as a problem. I think Apple switched before having to adopt v3.
Slides:
http://llvm.org/devmtg/2007-05/09-Naroff-CFE.pdf
Video:
https://www.youtube.com/watch?v=Xx7zFn31PLQ&feature=youtu.be
So there was a real technical need. IIRC, there was also a personal need, as Steve wanted to do something else, and I am sure not being dependent on gcc was also a big deal.
From long experience, Apple doesn't like to be dependent on others for crucial bits of their tech stack. Relations with the gcc team weren't the best, even without the GPL issues, although the new GPL v3 was also seen as a problem. I think Apple switched before having to adopt v3.