Hope is the first step on the road to disappointment. The universe is full of hope, as it is with despair.
Far too often will the desperate fools of the universe lay their hands upon the key to their salvation...only to have it snatched away.
So when Ahzek Ahriman of the Thousand Sons encounters such salvation, he does respond with hope, but with determination. He will restore his lost brothers, he will right his ancient wrongs, and he cut down anyone who dares to stand in his way.