A platform can't be held responsible for every opinion some idiot posts, true. When nations weaponize your platform to disrupt foreign elections[1] and facilitate outright genocide[2], you don't get to shrug and ignore it.
This is not just about selling data to advertisers anymore.
[1] https://techcrunch.com/2018/11/05/facebooks-election-interfe...
[2] https://www.lawfareblog.com/facebooks-role-genocide-myanmar-...