Computer Science can be taught without a student ever having used a computer; it's a branch of mathematics. Would you expect a mathematician to know what a .tar file is? Reminds me of a quote from one of the most famous Computer Scientists, who was really a mathematician: "Computer Science is no more about computers than astronomy is about telescopes." - E. W. Dijkstra (1930 - 2002)
This is true, in the purest sense of CS. However, how much pure mathematical theory can you fill three and a half years of university education with? I would imagine that a comp sci department where they never reach a point where the "rubber meets the road" is not worth the trouble.
...unless your rubber has already met your own personal road long ago. I, personally, learned everything practical I needed to know about programming long before I stepped into a CS class, mostly from self-teaching and the web; I only took CS to "straighten out" my theoretical knowledge. I would have loved a CS department with no computers installed (except perhaps for interactive debugging after it's already clear that you can express yourself in pseudocode.)