I think it’s important to make a few clarifications here.
1) Hope vs Expectation: Having hope (a dream or vision) is essential for motivation, and consequently success. The good book states: “without a vision my people perish.”
2) If a party has a duty to provide value, you have a right to an expectation. Sadly however, many a time we make our expectations another’s obligation, even though we entered into no such agreement with them. For example if an employee fulfills the goals and objectives agreed with an employer, she has a right to expect the reward promised.
Outside of a contract, legal or social, I wholeheartedly agree we should have no expectations while we keep hope alive.