Comment by theSherwood

It's not just about malleability. It's about specificity. A prototype has to specify certain details to run at all. This is not really true of sculpting in clay (former sculptor here). What the article describes of a sculptor working from big forms to smaller forms and so forth is in contrast to what it feels like to code by hand, which always requires some thought for the details even if the details are going to change dramatically as the program goes from prototype to hardened production software. The programmer always had to have their hands on the details even as they thought about architecture, but that's not the case now. Now we really can work from primary masses to increasingly specific details.