English teaching in China is highly fragmented. Unlike other industries where one or a few companies dominate, English teaching in China has many big, medium, small, and micro-companies.
Along with the developing economy, both foreign and indigenous enterprises need native talent who can implement Western method of education in China. Many new graduates decide to start their careers as a teacher in China. Some of the ex-pats end up teaching in China because of their interest in Asian culture.
No matter what kind of intention you may have, teaching in China is meaningful for your career and even entire life.