O’Brien lives in a mansion, with a servant. He eats the best food, everything around him is first class. Winston and Julia live in horrible circumstances surviving on scarcely edible rubbish.
Were Winston and Julia capable of thought, they would ponder why O’Brien would sacrifice what he had to ‘revolt’ against Big Brother?
Despite the evidence in their face, Winston and Julia’s innocence makes what is obviously going to happen to them even more tragic.
They are walking to their own destruction, willingly. They are agreeing to perform horrendous acts to gain nothing; for O’Brien makes it clear, that they will gain nothing, only lose.
If anyone had ever tried to discourage anyone from joining the revolt, O’Brien has.