Teaching produces educated people. College instructors, after all, have as much to complain about in the state of the world as anyone else. Usually, people who went to college. Teaching energizes research. Discussions with students who ask naive questions and attempts to help people understand fundamental concepts can result in new visions and directions for research.
Teaching is good experience.
There are few jobs where teaching experience would not be an asset. By the nature of the classroom, teachers have the power to bore their students to tears or to make their lives more entertaining, rich, and thoughtful. When this happens for the students, the instructor is never bored either. There may be a trend in academia toward a more balanced view of the university's mission.