I assume the problem here is with whoever invented the robots. He probably felt yucky attaching numbers to human lives so he made the robots evaluate every human being homogeneously. This mistake must have cost millions of life-years across the planet. But who cares? We wouldn't want Mr. Robot inventor guy to feel bad about pricing human lives.
All this talk about weighing the relative value of human beings is starting to make me feel like a bad person. Let's talk about that.
It seems to me that we're going to price human lives either way. Either you can do it in an informed, deliberate way to make things better, or you can do it in an uninformed, unthoughtful way to make things worse. There are many factors you could take into account; quality of life and influence on others come to mind, but the most obvious and easily measurable metric is expected remaining years of life. This is the one Will Smith seemed to endorse in the movie.
Even this metric can feel yucky. It's easy to make sentimental arguments about not privileging one life over another and caring about the elderly, but I fear this is a situation where being sentimental impedes our ability to be helpful. After all, we use straightforward logic when we think about ourselves, but we subject others to our illogical feelings. Seems pretty selfish.
Would you rather die when you're 30 or 80? Well, 80 of course. So why would you evaluate other people differently? You price your own life at 30 higher than you price your own life at 80. The same logic works when you price other people's lives. Why not treat others the way you treat yourself?
When you save an old life 1 person gets to be old, when you save a young life 1 person gets to be young and will probably get to be old too! Saving a young life is the same thing plus more! This is why life expectancy went up so much when we started to lower infant mortality.
Two people fall from a cliff and you only have time to save one. One of them has terminal cancer and the other doesn't. Who do you save?
Consider: Life is a terminal disease. We're all falling from a cliff, we're just falling for a really long time. We're all going to die, but some of us sooner than others. Make the right choice.