I think one major issue with FB's stance is they say they are not a publisher but rather a platform.. of course, they do tend to use whatever is convenient to them sometimes.
https://www.theguardian.com/technology/2018/jul/02/facebook-...
https://www.theguardian.com/technology/2018/jul/02/facebook-...
That's certainly not a universally agreed upon perspective. Just because you're a private company doesn't mean you can do anything you want (eg. discrimination), hence the existence of regulations.