Paul Graham responds, "They've taken something from chance."
One should be charitable because it's human to be compassionate to your fellow human being, not because being successful automatically puts you in debt to the God of Chance, which debt should be repaid or else. And not because by being successful you stole your success from somebody else.
But not so many understand or realize that.
Next time, they shall be born alone, let's see how many hours they survive.
People feed you. Build stuff for you. Make your life better. And most of them, don't gain much from it. Usually, they just die younger.
Unless you are a king, dictator or some force of evil. Building 99.5% of the wealth in the world will mandate you to build empires of business, solve problems, provide employment to millions of people around the globe.
That much doesn't happen merely by chance.