Why people just cant work harmoniously?

Mr M is working accordingly all this while. Accordingly here means he works according to the office hour. He would not take leave if he was not asked to. He tries to get alone with all his staffs and colleagues well. However, the green-eye monsters just can't sit still seeing him having a well and stable life. Then, people started to back stab him and his personal security is threatened. He has no choice but resign. Pity him. He has to start all over again in an entirely new area and job. Why are there green-eye monsters in this world?? To hell with them and SHIT!!!