[pjmlp]

C's success in the industry is largely tied to UNIX's success.

As UNIX systems started to spread into the industry and getting market share from mainframes, developers also wanted to have those utilities in their home systems. This lead to C being spread outside the natural environment (C) and "infecting" non UNIX systems.

As Pascal refugee, I only touched C when required to do so. Even with its quirks I find C++ offers a more welcoming place, thanks to its stronger type improvements and better abstractions over C.

Like any systems programming language, C will only get replaced if the operating systems vendors force developers to use something else.

This is what Microsoft is doing by transitioning Visual C++ to a pure C++ compiler.

UNIX vendors will never do it because C is synonym of UNIX. All even C compilers get to be written in C++ nowadays.

Who knows what other OS vendors might still be relevant.