Mark Guzdial, one of my graduate school advisors, just posted on why computing education is important to him.
No, we're not about curing small children. But we are creating the infrastructure for a lot of important work. Literacy is powerful. The people who invented writing did not cure disease, but by inventing writing, they made all of science possible, not just medicine. Perhaps the medical researcher who first understands how autism works will come to that understanding or will communicate it by creating a computational model of autism. And maybe that medical researcher is in our introductory computing classes today.
His answer fits well with mine. Computing is a new tool for thought, all kinds of thought. It helps scientific research, business, education, art---anywhere a mind is active, computers have found a way to help. Computing will be as fundamental as writing, so it is worth teaching the craft as we know it, and it is worth trying to improve that craft.