Isn't react open source though? Why would you care about the source of it if it serves your purpose? Facebook doesn't make any money off react or as far as I know use it for political leverage. Can you point out why you'd quit using a technology because the person/company behind it is "bad" ? The Nazis improved rocket technology tremendously during WW2 and we didn't toss that knowledge because the Nazis invented it.

Its not just about the react being opensource. Its the philosophy that drives the ecosystem. Facebook can come up with a react component for VR on the browser which work's really well only with facebook account.

The analogy would work better if the Nazis were still around and handing out rockets for free, to make it easier for them to hire engineers who know about rockets, so that they can launch better rockets at people.