Watch this.
Terry Gilliam makes a good point, but it has been made before--by Aristotle, among others. Great tragedy requires the author to take the story all the way to the correct ending, according to Aristotle, who uses Sophocles as his example of a perfect playwright. No one wants Oedipus to pay for his accident, but his mistake cannot be undone. There is no going back after you kill your father, marry your mother and raise 4 children with her. Not even the legacy of a good kingship can do that. Tragedy is pre-freudian, I think. Not what you meant to do, not why you might have done it, just what you did. The gods judge us on what we do.
So back to Gilliam: happy endings feel good in the moment, but if art imitates life (and you can argue this if you want), then we have all felt the sting of reality at the end of one of our episodes, when the fear and doubt of the Chorus in the stasimon is indeed played out in the denouement. Having the guts to write it that way may be what separates the good filmmakers from the great ones.
And I still don't know what the end of 2001 means. I feel better about that knowing Terry Gilliam does not either/
for more on Gilliam:
my review of 12 Monkeys:
