OK, so it seems to me that you pretty much agree with my argument, but you don't like my assumption that even if there is subjectivity, there can be a learning

OK, so it seems to me that you pretty much agree with my argument, but you don't like my assumption that even if there is subjectivity, there can be a learning algorithm. Is that correct? I think even for 100% subjective decisions we can construct an algorithm as follows. Take the same inputs that a person (making the decisions, for example to hire) takes as input to the algorithm (well, at least try to take in reasonable number of parameters). As an example outcome, take the subjective decision that would same person (or committee, what you have) make after a certain period of time, say 3 months (when it becomes more obvious whether the original decision was good or bad). Then you can train your algorithm (but then it will, obviously, depend on specific people involved). And I think it can possibly perform better than the person for the reason I outlined.