I completely disagree with your premise.

Assuming that you are talking about the theory of computing, I would argue that it is essential to writing good software. Knowing the difference between an array and a hash, or when to use a linked list rather than an array, is quite necessary for writing good software. Anyone can churn out a script to accompish a given task, but whether it's well-written depends on whether or not he/she/it understands what he/she/it is doing.

Having said that, computer science is not necessarily something learned in the classroom.

Most of what I know (which is not a great deal ;]) I learned through extracurricular study. I play with computers for the simple fact that I enjoy it. I like coding, I like admining, I like doing stupid things like dd'ing a kilobyte of hda over hda1 and tearing my hair out trying to fix it. On an arguably basic level, I have an understanding of computer science. Without it, I could not write good software. And without furthering it, I cannot write better software.

Attaining a degree in something is simply a means to an end, one of many. We're all free to choose a different route.