The key to get across to the kids, which is something my parents did a horrible job of doing, is that the universe, by it's very nature, is injust, and that will never change.

That sounds like something my wife would say. I disagree. I think the universe is indifferent. It's a fine distinction, but it matters. The good guy doesn't always win, any more than he always loses. "Winning" and "losing" are completely unrelated to who "deserves" what. (Except that the maturity to adjust your expectations can change the perception of what it means to win, but that's a whole 'nother matter.)