The basic idea of legibility is that the act of making something comprehensible enough to control is itself an act that shapes the thing to be controlled, often with far greater consequences than the control itself. This is because it removes complexity that is deemed as irrelevant that makes it harder to control, and that complexity may be in some way essential to the health of the system.
Robert Smithson and other so-called land artists simply disengaged from architecture, placing their works in America's open landscape, leaving behind the museums and galleries Smithson referred to as "tombs". A new "expanded field" allowed artists to contextualize their work beyond the institutional frame of the museum or the commercial structure of a gallery. Richard Serra, who also began to move outdoors, at times chose to "attack" architecture, creating structures that disrupted or overwhelmed the buildings around them.
The artists of the Light and Space movement took another tack. Rather than fight or flee the architecture, they explored and manipulated it, approaching architecture as a kind of found object, creating a series of rooms that incorporated architecture and architectural structures directly into their art. Bruce Nauman summarized it well: "When you work in a gallery or museum, the architecture is a given. If you wanted to have a show, you didn't have a choice, except to deal with it. You had to find a way to either absorb architecture into the piece of build your own."