In Harry Potter and the Methods of Rationality, Harry Potter plans to use the Philosopher's Stone to guarantee immortality for everyone. (Yes, ambitious goal, dreams are free, etc etc...)
Obviously, things are a bit different from HPMOR to Harry Potter canon, where: Spoiler! If you are planning to read HPMOR (and you should), DO NOT read the spoiler.
Nicholas Flamel is not an immoral transgender liar who claimed that the ancient relic (the Philosopher's Stone) was actually made (not stolen from the previous owner), thus shutting out billions of people from immortality.
In the original Harry Potter universe, why didn't Flamel make more than one stone? He already knew how to do it and he had done it before, why didn't he make more stones so that everyone else could benefit?
Surely a 'good' wizard—companion of Albus Percival Wulfric Brian Dumbledore, Order of Merlin (first class), Headmaster of Hogwarts School of Witchcraft and Wizardry, Grand Sorcerer, Supreme Mugwump of the International Confederation of Wizards, Chief Warlock of the Wizengamot, re-discoverer of the fabled Twelve Uses of Dragon Blood—would be concerned about everyone?
Note: not a duplicate of Why was there only one Sorcerer's Stone?, as that question is asking:
'Why did only Flamel make a Philosopher's Stone' (eg why didn't someone else make one)
while this question is asking:
'Why did Flamel make only one Philosopher's Stone' (eg why didn't Flamel make more than one stone).