Most entering graduate students bring in some knowledge of C or Visual Basic. Most do not end up on a track leading to a tenured position at a research university, and many go into computer-related fields. The job market for C programmers is vastly richer than for Fortran experts. This is true both at the local level here in Lexington and in national astronomical centers. Students would be far more competitive in the job market if they had several years of experience developing large-scale C programs.
Graduate students rely on the faculty to make choices that are in their long-term interests.
If we can get our work done in a C environment, we owe it to our students to do so. Unfortunately, the Open Source movement does not support Fortran beyond the f2c conversion utility and the g77 compiler. Modern compilers are commercially available but are expensive, making modern Fortran more like IDL than a true ANSI language. Most system shells and higher-level languages carry intellectual heritage from C. As universities change to better take advantage of the web, languages like Java, XGL, and SQL will become increasingly important. A C environment makes this both easy and natural.