It strikes me to observe how much pejorative the word utopia has turned out to be. This shift seems to be a trick of the system in order to operate an easier normalization of architectural projects. The Metabolists and Western Utopian projects from the 60's were definitely not perfect and they owned some bureaucratic totalitarian characteristics that recalls Kafka despite the fact that Izosaki seems to be familiar with this literature. However, the very important quality of these project is that they increased in a tremendous way the field of potentiality of what architecture could be. Those projects were Utopian in their participation to what the great French Philosopher and Poet Edouard Glissant calls Imaginary. Imaginary and Imagination are two different things in this regard. Imagination is the ability of an individual to produce virtual images based on memory. Imaginary on the other hand is a collective construction based on a common horizon to work towards to. Utopia is the territory of the Imaginary. What defines a totalitarian society is the absence of Imaginary -Deleuze would call it "devenir" (becoming)- and it needs a tremendous subterranean work in order to re-build a beginning of Imaginary within those societies.
The case of Western capitalism is interesting. In fact, instead of preventing Imaginaries to exist like a totalitarian system would, it has the ability to intrude and corrupt Imaginaries from the inside. This is true both in general and in architecture more specifically. The current case of sustainability seems appropriate in this regard since capitalism seems to have cannibalized what used to be a resisting Imaginary against it. That is how some new processes of normalization have been invented in order for capitalism to survive. As architects, we have the possibility to adopts those processes more or less voluntarily or to resist to them by still considering utopia as a tool rather than a waste of time.