First of all, Zhu Ziqing did not die of starvation, but of illness, due to a perforated stomach caused by severe gastric disease and overeating.
Secondly, as a professor, Zhu Ziqing did not lack food. His call to not accept relief grain is a typical case of moral blackmail, standing aloof and losing humanity for political purposes from those who truly need food.
Thirdly, Zhu Ziqing's son was executed by firing squad in 1951, reaping what one has sown.