[nithril]

From nothing to result rarely happens in real live. I hardly see someone to start/stop a program per unit task (like piping commands).

[jltsiren]

Code compilation is a common example. In many languages, when you do a clean build of a large project, you run a large number of short-lived processes.

With command line tools, the dominant design philosophy is that a program completes one task and exits. The tasks may be large or small, and the same tools are often expected to handle both.