Has anyone ever noticed that the Jetsons are one of the only "happy" examples of science fiction? There are no obvious enemies to the future world they live in. The cartoon is a comedy, so it feels good to have no bad guys? So can we still consider it science fiction without the bleakness? Is bleakness a characteristic of science fiction?
Common science fiction novels and stories are always fighting against something, whether it be an oppressive government. Or there are people in trouble.
For example, Star Wars has the Empire. Darth Vader is the evil enemy of the story among others. Star Wars constantly has a depressing feeling to it in the long run. Some sort of enemy has to be defeated in order for the characters to overcome their bleak situations. Happiness is only achieved through the defeat of evil.
Furthermore, 1984 is trying to overcome an oppressive with too much control. Again, the story always has a bad outlook. There is a constant sense of overcoming a depressing situation. Fahrenheit 451, Anthem, Brave New World, etc.
Why is science fiction so depressing and why are the Jetsons so happy? Are they science fiction? They take place in the future and have space ships that defy gravity and hovering vehicles. The only bleak events in the Jetsons are quickly overcome. For example, George Jetson is constantly fired by Mr. Spacely but then subsequently re-hired.