Christopher Alexander on patterns:

The idea that materialized in the published pattern language... was done in a way that would allow this to happen on a really large scale. And, what I mean by that is that we wanted to generate the environment indirectly, just as biological organisms are generated, indirectly, by a genetic code.

Architects themselves build a very, very small part of the world. Most of the physical world is built by just all kinds of people. It is built by developers, it is built by do-it-yourselvers in Latin America. It is built by hotel chains, by railroad companies, etc., etc...

One of the characteristics of any good environment is that every part of it is extremely highly adapted to its particularities. That local adaptation can happen successfully only if people (who are locally knowledgeable) do it for themselves.