How does it make logical sense? People are not numbers. What right do you, or anyone else, have to decide who shall live and who shall die?
Reducing people to numbers is a logical fallacy in itself.
Change the 5 people to millions. Now it's one person vs. millions.
The choice is now even more obvious. And if you don't consider the numbers in this case people will call you a psychopath if you can't see the difference in moral weight between millions and one life.
Numbers are indeed part of the equation.
For example a researcher choosing to sacrifice a healthy individual to donate their immune cells to save a million terminal cancer patients is considered morally reprehensible because people can’t to see how the researcher could be considered responsible for the a healthy individuals life. If the individual goes from being healthy to being in a coma and researcher becomes family member the question then becomes morally ambiguous.
If morality was a universal concept there would be nothing ambiguous about it. It would be logically consistent. But what we observe is that we can trigger inconsistent moral situations.
This very example. This very topic is evidence to that fact. The moral conflict described as the topic of this HN article is consistent across populations across cultures. It is genetic. It is not learned.
In fact we can actually identify physical and structural difference in people who lack morals. Psychopaths, people who innately lack a moral sense. The differences can be literally seen as a physical manifestation of an actual 3D coordinate of the brain. A researcher who studies these things can actually tell you if you're a psychopath or not just by looking at a brain scan.