Stallman on GCC, LLVM, and copyleft

>All the discussion above about licenses and what RMS does or says is a red herring. The only reason why GCC is lagging behind LLVM is lack of developers, and more concretely, a lack of full-time overall leader developers with a clear vision for the whole compiler.
Why do you think GCC license does not affect the willingness of developers to work on it?

My previous company contributed to LLVM because it's being used in-house for several projects (as a JIT for a certain matching engine). They had zero interest in contributing to GCC because its license wouldn't allow to use this JIT in products shipped to their customers.