True, as stated by the quip "Computer science is no more about computers than astronomy is about telescopes", which is mis-attributed to Dijsktra (http://en.wikiquote.org/wiki/Computer_science) but still very much true I think.

The blame is not all on the student, though. It's on CS departments that present a vague picture of what they are doing. Some of these focus on mathematical aspects, some on AI, etc.