Thanks for your feedback.
Perhaps we did not sufficiently emphasize it in the blog post, but we do tell the students about strong existing architectures, open source as well as from industry. The books listed in further reading in the post actually contain chapters about git and emacs, and I share your enthusiasm for Bentley's little language approach.
The philosophy of the course is based on trying to apply published approaches to software architecture (such as those in Rozanski & Woods' book, but it could be others) to real systems actually maintained and used. We encourage to get in touch with the creators of those systems.
The students actually take a deep dive into a foreign code base -- I included pictures because that is easy to share in a post, but the students analyze code, report about that, execute test cases, deploy systems, etc. The pictures are indeed, as suggested by some of the others, means for communication.