[clang-tidy] Using ccpcoreguidelines checks on C99 code

Hello,
I am currently working on my bachelor thesis which is “The Tool for Assessing the Neatness of Source Code”. Generally speaking it focuses on the most common beginners mistakes in terms of readability and the tool is intended to use at our faculty in course “Introduction to Programming Systems”.
I decided to use Clang-tidy to realize some of the checks. Some of the build-in checks from cppcoreguidelines attract my interest. For example avoid-goto or macro-usage. However when I tried to use them to check C99 code examples, which we use in our course, it won’t warn at all. After some code inspection a found out that reason for is built-in function isLanguageVersionSupported in .h files, which is hardcoded for C++ codes only.
So I would like to ask, is there any more reason besides that these check came from C++ guidelines, that these check are locked to C++ code?
Because even in our C course it teachs avoiding using goto, macro function etc. So these check would find use even on C99 source code.

Thank you