Thing is, embedding binary files is not that useful, and there are easy enough ways to do it for those few that really needed it.
The C standard has been very cautious about adding features that would make the standard and the compilers more complex since it is the lingua franca of computing.
Nowadays there is really just a handful of archs in use and their compilers are all backends for GCC/LLVM, so they are relaxing a bit the gating of features.
