[dspillett]

> the objective function of a piece of software is now more important to get right than the implementation

That has always been the case. That is why weeks or even months of programming and other project busy work could replace a couple of days of time getting properly fleshed out requirements down.

[sanderjd]

Agreed, it has always been the case. But I've never thought of it that way so explicitly. And I might argue that the important distinction is that the objective function is programmatically verifiable (which the word "requirements" has not always implied).