Balderdash. A lot of smart people got together and built something that makes getting to a working product faster for you than if you had done it all yourself. This is the core of what makes us human and allows us to advance as a species. This kind of attitude would have us still living in the dark ages with no electricity or running water. How about be pragmatic and use what is out there, learn from it, and contribute back to the body of knowledge so we all get that much smarter? 10 years from now ReactJS may or may not just be a distant memory, but the legacy of development and thought that it has spawned will live on in whatever next thing comes out, and that is the true sign of something worthwhile.
Stop worrying about the arrangement of source code behind your apps and build things that delight, engage, and change the world.