It may be technically correct, but C++ and now JS have a "class" keyword for a reason, and that's to steer you towards organising your code into classes which operate in certain ways. In both languages you can avoid using classes, sure, or abuse classes in various ways. But fundamentally they do have classes.
But that’s the point. The way in which classes operate in JS is different from the way classes operate in OOP focused languages like C++, Java and C#. That’s because the language doesn’t have classes, but rather syntax to make it look like it does. On the surface your code will be organized in similar ways but the underlying behavior is different.
I guess, yes, there's different semantics between the constructor and componentDidMount, but it's UI library, this is common that "when a constructor is call there is no guarantee the component has actually mounted".
You can't `new MyRecyclerView(...)`, you've got to `LayoutInflater.inflate(MyRecyclerView, parent)`, which isn't any different from `React.render(MyApp, parent)`.
Was the issue with `this` in componentWillRecieveProps not solved by using an arrow function? If so, that just sounds like normal JS binding woes.
Facebook recommend composition over inheritance, but you can totally extend React.Component and even get abstract classes involved. In my custom React renderer, all the components in the library are based off React.Component class inheritance.