> I guess this is for when you're knee deep in terminals?

One can use it directly in terminal or it can be used as a dependency tool in other scripts similar to the way other UNIX tools are used. For example I use it as a pronunciation player in my dictionary dict-master [1]. It's a shell script too.

Another example (run two times so it uses the cache the second time):

  echo this unix pipeline is poor man text to speech | xargs -n 1 gsay