There are a lot of cases even on bigger SW projects when for some roles(designers, tech writers) just basic git skills would save a lot of nerves to developers.
Designers can fix small things, like images, tweak html a bit etc. They dont need to know how to create/merge new branches etc..
I dont see that Git is trying to pretend that its simple but i can see how that interactive tutorial can be incredible useful to a lot of people.
Github wants to explain what Git has to offer you. I assume they want to see you as a potential customer, and if nothing else it gives you a real live low-risk git repository to play with after you're done with the tutorial.
Designers can fix small things, like images, tweak html a bit etc. They dont need to know how to create/merge new branches etc..
I dont see that Git is trying to pretend that its simple but i can see how that interactive tutorial can be incredible useful to a lot of people.