But that is not a result of the licensing, it is a result of a design decision. While it may very well be that such a design decision was made to avoid GCC bein

But that is not a result of the licensing, it is a result of a design decision. While it may very well be that such a design decision was made to avoid GCC being used with proprietary front-ends (along with the fact that GCC is simply an older project), it does not provide an argument against GPL, at best against some choices made by the FSF. And after all, the LLVM license is the reason why people have to hope that Apple will open Swift, as opposed to that being a fait accompli. And the LLVM license is the reason why hardware vendors will be able to build proprietary back-ends. In my book neither of these facts increases freedom.