Why is utopia nowhere? Utopia will always remain nowhere because it implies the unending critique of all structures which establish and serve exclusion and inequality. It is the continuous practice of democracy.
Utopias are often based on architectural models, or on rules about the division of labor and the ownership of land for instance. However, it seems to me that little is being written about the need for the powerful binding that keeps people responsible of each other, and that make them feel part of a same common society.
History is packed with examples of how imaginative representations have been used as mediators to investigate or communicate the possible world thought out of its limits.