For many people, Ji Xinghe was treated unfairly, but for Ji Xinghe himself, the life he leads now is the path he was supposed to be on.
Master Liu's recruitment was accidental, Colonel Chen Xun's philosophy of 'Using people and things to their full potential on the front lines' was also accidental. The battle with Han Li, his becoming a special guest instructor at the Base 6 training area, and his subsequent attainment of a level 3 mecha warrior license, were all accidents stemming from other accidents.
Many people believe that Ji Xinghe, being sent to the general repair area, must be very dissatisfied and could cause some serious issues at any time, especially after hearing he threatened Colonel Tang Qiao. However, the reality is that even though Ji Xinghe may be dissatisfied, he will not act on it.