Why is it so unintuitive to specify custom commands?

[nush-1qb]

I am looking at the example for how to build and publish a docker image, and the command that actually works is like this:

                arguments:
                - -c
                - docker build -t $DOCKERHUB_USERNAME/bulletin-board:$GO_PIPELINE_LABEL . -f Dockerfile.application
                command: /bin/bash
                run_if: passed

This seems like such a round-about way of calling docker build. The existing docker build command that is provided by the default command repo is broken too.

What's up with that?