Teaching is a valuable skill and whether students will continue in academia, move into industry, or chose a different work option, all students are required to teach for one semester at a 50% appointment or for two semesters at a 25% appointment.
Teaching is often one of the most effective ways to learn something, learn how to communicate and articulate ideas and methods, and strengthen one's own comprehension and mastery of concepts. Effective communication skills and ability to explain research is a valuable skill.
At times, students are unable to hold a teaching assistantship due to a fellowship or training grant restriction. In these instances, students can petition for alternative arrangements.