From the latest draft of The Case Against Education:

The permanent residents of the Ivory Tower
often congratulate themselves for broadening students’ horizons.  For the most part, however, “broaden” means
“expose students to yet another subject they’ll never use in real life.”

Put yourself in the shoes of a Martian
sociologist.  Your mission: Given our
curriculum, make an educated guess about what our economy looks like.  You would probably work backwards from the
premise that the curriculum prepares students to be productive adults.  Since students study reading, writing, and
mathematics, you would correctly infer that the modern economy requires
literacy and numeracy.  So far, so good. 

After this point, however, you would proceed to make
one incorrect inference after another. Students
have to spend years studying foreign languages, so there must be a lot of jobs
for translators.  Students have to spend
years studying history, therefore many go on to be professional
historians.  Students spend years “studying”
physical education.  The natural
inference is that there are plenty of jobs in professional sports.  A year in visual or performing arts?  There must be ample demand for actors,
dancers, musicians, and painters.  Teachers
emphasize classic literature and poetry. 
A thriving market in literary criticism is the logical explanation.  Every student has to take algebra and
geometry.  The Martian sociologist will
conclude that the typical worker occasionally solves quadratic equations and
checks triangles for congruence.  My
point: Although we can picture an economy that fits our curriculum like a
glove, this economy bears little resemblance to our own.