Implementation details largely determine how fast a given program will run.
C makes it rather easy to predict how fast a piece of code will run, and what its bottlenecks will be. Lisp makes that rather hard.
Given that there are always programs that need to be as fast as possible even with hand-optimized algorithms running on top-of-the-line hardware, C will win for many applications that have even moderate performance requirements.
Also, current mainstream operating-systems favor C and C++, if only implicitly.