> Is that really an advantage of C over C++?
You may find that not all C++ features are supported for the least popular processors or for old ones.
Standard C++ threads, for example, were not supported by GCC for Windows for a long time. I do not know what is the current status, thou.
> This is the big advantage of C. If doesn't run C, probably it just doesn't run at all.
Is that really an advantage of C over C++? They have identical runtime requirements and typically share a common compiler (although one of those, MSVC, barely supports C). Is there actually anything that can run C but which cannot run C++?