>Perhaps, like any other tool-set... C has an optimal problem domain not everyone can understand

Maybe this is true specifically for C. However you imply this is true for "any other tool-set".

This is also a form of bias. It is illogical and irrational to think that every tool set is good for something. Things that exist can be horribly bad for everything and things that exist can in theory be good for almost anything.

There is not magical rule that says all tool-sets are great because they're always optimal for some niche problem domain.

The universe is not made up of apples and oranges. There are rotten oranges and rotten apples as well.