OOOF. Do you mean in terms of morality or in terms of functionality? Not my place to teach you morals (or ethics), and not because I do not have very strong opinions as to right and wrong, but in a moral evaluation, "good" means doing what is moral, acceptable, and "bad" is doing what is not acceptable. As to functionality, good means doing it in a manner that achieves the goal of the effort, and bad means not achieving the goal.
All words having a subjective meaning depend on the ideals of the individual and the context of the use. Good and bad are definitely subjective terms. good is what you think it is.