> Companies release these libraries because they benefit the companies. The successes of projects like React help Facebook.
The success of projects like Haskell and OCaml help Facebook too. Should we consider not using those technologies?
It seems the only difference you can point out is that Facebook "owns" React. But this doesn't make any practical difference when it comes to open source. It's like public transportation. If Facebook sponsors a high-speed railway that benefits both them and two cities, so what? That's great for everyone.
If you were talking about a paid SaaS run by Facebook, then I would agree with you. That would be more analogous to supporting Uber than supporting public transportation.
Facebook's use of software is completely different than a product of Facebook that targets programmers. Companies release open-source libraries because they benefit the companies.
Companies release these libraries because they benefit the companies. The successes of projects like React help Facebook.
I think that people who believe that Facebook is an unethical company should consider alternative technologies on new projects whenever possible.