Camus is talking about Absurdism. [1] How it's related to the Nietzsche's quote depends on how you see it. (Nietzsche was a kind of absurdist himself)

It is a broad theory. It says life is basically absurd because the world is meaningless and indifferent to man's desires/prejudices/beliefs. The world just doesn't care about man and we can't apply any universal laws to human life. Life is full of randomness/surprises. Loss/defeat/death can come anytime in any form but man continues to be in denial about them. This makes man vulnerable to boredom/pessimism/nihilism. I think this situation is what the article's 80% of people represent.

The solution Absurdists give is, man should create his own meaning in life and live for it but by being constantly aware of life's absurdity. Instead of denying it or seeking permanent happiness in some supernatural world or after life, we should embrace this life and all its absurdities. This attitude makes us live life to the fullest and as Nietzsche says it leads to the 'celebration of life'. I think the article's 20% of people fall under this.

[1] - http://en.wikipedia.org/wiki/Absurdism

Also see:

The Myth of Sisyphus - http://en.wikipedia.org/wiki/The_Myth_of_Sisyphus

Eternal Return - http://en.wikipedia.org/wiki/Eternal_recurrence#Friedrich_Ni...

Amor Fati - http://en.wikipedia.org/wiki/Amor_fati