It would be far easier to add as builtins the features that are missing to GCC than change the language, that would involve rewriting a ton of code (even switching from C to C++ they are not 100% compatible, also, they may introduce bugs difficult to spot cause their incompatibility). The Linux kernel already uses a ton of GCC extensions (even the min/max macros suggested in the article) that is not compatible with other compilers anyway (and I don't see a reason to be, since GCC is the compiler of the GNU project anyway, unlikely to compile the Linux kernel with MSVC, or even I don't see much reasons to use clang anyway).