You seem to be confusing the concept of a language with the concept of program used to write in a language. DEML is a language (that's what the "L" is for). A program with a UI, graphical or otherwise, can be used to create a DAG, and then that DAG can be saved in a DEML representation.

With that in mind, what you seem to be bothered by (please correct me if I'm wrong) is actually that a language has been released without a UI to abstract away the process of writing it?