I'm not really an expert, but my understanding is that the perception from the Apple side is that GCC was basically ok, and they were happy to contribute to it, until the FSF switched to GPL3, which they view as freetard nonsense and totally unacceptable to their needs.
My understanding is that the perception from the GNU side is that everything was great and productive with Red Hat, IBM, Apple, etc. all contributing together to one compiler, and then because of Apple's misguided objections to GPL3 and GNU, Apple decided to take its marbles and go home and start funding and working on a new compiler suite. Now we have some companies contributing to GCC and others to LLVM/Clang and there is a lot of over-the-top criticism of GCC. I assume the GCC people also wish they still had all the resources they used to have.
That's why I get the sense the competition is not so friendly.
My understanding is that the perception from the GNU side is that everything was great and productive with Red Hat, IBM, Apple, etc. all contributing together to one compiler, and then because of Apple's misguided objections to GPL3 and GNU, Apple decided to take its marbles and go home and start funding and working on a new compiler suite. Now we have some companies contributing to GCC and others to LLVM/Clang and there is a lot of over-the-top criticism of GCC. I assume the GCC people also wish they still had all the resources they used to have.
That's why I get the sense the competition is not so friendly.