People are absolutely irrational creatures.

> Man likes to think of himself as a rational animal. However, it is more true that man is a rationalizing animal, that he attempts to appear reasonable to himself and to others. Albert Camus even said that man is a creature who spends his entire life in an attempt to convince himself that he is not absurd.

-Elliot Aronson, "The Rationalizing Animal"

Or to be less philisophical: the people with the money and power to say what's important are rarely the ones thinking long term, nor in an audience of other powerful, rich people thinking long term. US congress' median age is over 60: most aren't thinking about how to keep the Earth alive in 20-30 years. They won't be around to suffer the consequences.

Capitalism*