Because if people could remember what 100 years ago Earth was like, they'd know that the best things to happen in the last 100 years are based around the idea that if we all work together, then when we're old, we will take care of each other. And when we're young, rather than work like adults, we will teach our children with the collective knowledge of our species so we can continue to advance. We can afford to take care of those who can't work like the rest. Too much of the time, we choose not to take care of those people.
