I personally don't give a crap if any art work has to be realistic. The Roddenberry vision can be seen as it is, as a hope and dream.
Unrealistic TV shows are fine. But don't be surprised when a long-running franchise like Star Trek
that depicts an unrealistic humanity eventually examines the flip-side. Don't be surprised when they eventually examine the cost such a society would have, the the things people would be willing to do to protect it.
When they present an "unrealistic" humanity, they open up other storytelling options in the process.
I don't care. Since I see works for what they are in their context. Nobody in this thread has frankly mentioned why all artistic works need to be realistic.