What you raise is a valid concern, but is it better for a new developer to work off a best practice style example app or try to reinvent the wheel on their own?
A new developer by definition doesn't know what best practices are, so they can't judge whether the example app they're working off of is safe or not. By way of a too-abstract analogy, learning multiplication tables is not reinventing the wheel.
I agree. I know a lot of developers that will benefit having a good example to work from.
No doubt I agree as well. Best way to learn is by imitation. But yeah, it is just a concern, that's all.