Having used Angular for a month or so in summer, I find prototypal inheritance horrible and unpredictable. I am never 100% sure if the data is coming from or updating the parent object or the current object. Class based inheritance seems a lot more predicable to me.
You can have OOP without classes - prototypal inheritance for example. In JS, you just clone an exemplar with Object.create() for example.
That said, the article author does the same thing.