Higher education is not a vocational school (with the exception of certain majors like engineering).  It is a process of learning how to think, analyze, solve problems and communicate.  Becoming accomplished at mastering skills like linear algebra will be a skill that one can use in almost any career.  And the more capable one is in being able to master skills like this, the more potential one will have in a career----even if the specific skill is never used as part of the job.