The documentation only seems to describe the GET operation. That being said, the Exclusions are not mentioned at all, and they also seem to have atleast a GET operation. Thus the documentation might not be complete.
I second this request for programmatic automation creation.
One of the many use cases - I want to have an ordered list of automations, and enter each user into the first automation whose entry criteria they satisfy. This would be easy to do with a programming language. With my current understanding, using the GUI for this would be tedious and error prone.