Why don't you teach X?
Data visualization, high-performance computing (HPC), Perl: the list of things we don't teach is much longer than the list of things we do. As with every curriculum, the question is not, "What would we like to add?" but, "What are we willing to take out in order to make room?" We believe our core topics are the absolute minimum researchers need to know in order to do computing well. We also believe that topics like data visualization are covered well enough elsewhere.