C and what came after it, C++ (++ is the increment operator in C++, so as a joke they called the upgraded version of C C++), are used because of performance. Actually, very few applications that are precompiled run in anything other than C or C++.
C/C++ is a general purpose high level very powerful programming language, hence its use all over the place. Java works great if performance is less important than portability, as it will run on any computer with a JVM. VB runs in a similar manner, but only on MS operating systems. Other competetors include FORTRAN 77, or just F77, used mostly for scientific calculations, BASIC, which lacks almost any power, Pascal and Delphi, which are also less powerful than C and COBOL, used for programming custom business applications because it’s very easy to program. C, C++ (and to a lesser extent B, which came before them) are very powerful and easily optimized programming languages.