I think you’re overlooking that they are publicly traded companies.
The opposite of private ownership is not publicly traded companies, it’s state owned companies, or government organisations.
It’s a bit of a stretch to say that because they’re publicly traded that means things are a-ok with them assigning scores to people. The most vulnerable of which never would even own stock in any of those companies, and even if they did, not enough to ever be able to influence their practices.