> Most kitchens and bathrooms are unused most of the time, but that doesn't mean every home having one is bad.

isn't communal living the most efficient thing resource-wise though?

No, he was not saying that was his goal! That's what everyone seems to misunderstand about this quote.

It's like a highrise developer saying "people think our buildings take up a lot of land, but actually houses are much worse from a land use perspective". Which is objectively true, and yet does not mean the developer thinks the entire world should be turned into houses, or even that they dislike houses!