Many schools rely on adjuncts and lecturers to teach. They get paid very little, have no job security, no benefits, etc. But because the academic career path is so completely broken, lots of of very smart, talented instructors take on these jobs to make ends meet while they look for something else that allows them to pursue their passions with their extensive educations.

Don't look down on these people. They're smart, they work hard, and they deserve better.