You are correct, all terrorist should be killed. But let us define who is terrorist? Are those people trrorist who kill minors in Ghodra? Or, who killed and raped people in Nandigram?
Or, do you think all people who are muslims are by birth terrorist?
Just think for 5 mins, you will get your answers :)
YOu will find that yes Modi is terrorist, Bhudha is terrorist. They should be hanged till death.