Mamet is in no sense a Christian, but his observation of life at this point is one we share. The Bible teaches us that people are not good at heart: every part of us is tainted by sin. Nevertheless, neither we nor the world are totally and unremittingly evil, and in the goodness of God, we often manage to work together to do and build good things (if not perfect things), and to live together with a degree of harmony—but only to a degree, and never without suffering and compromise. It's not the system that's the problem—such that if only we completely changed it, everything would be fine; it's the people.
I don't think Tony is intending to make any sort of political point. Perhaps I'll ask him next time I see him. But he does here what any good theological thinker must do, which is to take the basics underlying our world-view and subject it to scrutiny using the Bible's teaching.
And the Bible is has no shortage of passages that remind us of our fundamental corruption.