Comment by nrclark

I'd say say there's some truth to it, but maybe in an accidental way.

Shell scripts have been part of UNIX since day 1. A lot of early UNIX commands were implemented as scripts, and shell was always intended to be one of the main extension mechanisms for users. Scripting is fundamentally based on the assumption that a script will run various commands, glued together in a user-specified way.

So it's true to say that most early UNIX commands were designed to be useful in a script, which implies that they were designed for use by programs. Maybe not designed _exclusively_ for use by programs, but definitely an important design consideration.