Because the C language is like Latin - it is finite and has not changed for years. C is tight and spare, and in the current economic climate we will need a host of young people who know C to keep existing
critical systems running.
C is built right into the core of Linux and Unix. The design idea behind Unix was to write an
operating system in C so all you needed to port it to a new architecture was a C compiler. Linux is
essentially the success story of a series of earlier attempts to make a PC version of Unix.