I used this once to illustrate software development work to non-technical colleagues. It succeeded in showing them how many small changes from many people come together into the final product.
I liked using it as a motivational tool, to remind myself how far a project had gone and how I'd contributed, but that's about it
Pretty, neat, attracts crowds for once or twice. Didn't know how to make use of it.
Pretty neat, not that useful because non-interactive video visualizations rarely are. Also can be used to visualize other things. I've used it to show forum activity for example.
Non-interactive video visualizations were useful for decades before interactive ones became available, and still are when done well (which isn't as rare as you imply). They also reach a much wider audience.
I have used it several times when presenting the stuff we have done at my current job (i.e. show how we have grown from a 2 person startup to a 15 Engineer shop). Undergrads like it a lot.
The only thing that I think it is missing is having a "size" of each node to represent the size of the file. That will give a lot more visibility on changes.