He felt that war was bad because, even though it might benefit some individuals involve, in the sum total, it is still more negative.
Ultimately, war like so many activities was reprehensible because it was based in selfishness. For Mozi, selfishness was the root of all societal problems.
Mozi’s emphasis on maximizing useful behaviors and reducing all unnecessary expenditures or activities can be called a “utilitarian” theory.
Utilitarian means the main objective is what is most useful for the welfare of all, rather than individuals.