Social media is necessarily going to have racism, idiocy, profanity, conspiracy theories and everything else. If you start having editorial standards, it's not social media anymore.
Is Coca-Cola genuinely worried that their ads might appear alongside a rant about immigrants from your right-wing uncle? I think there is an ulterior motive but I'm not sure I can figure it out. Perhaps they sense that controlling the "woke" narrative works in their interests as long as it prevents people from going toward genuine radical and leftist, anti-corporation ideas that might question how Coca-Cola is addicting people to sugar and causing diabetes, how it treats trade unionists in Latin America, and things like that. So Black Lives Matter, as long as they drink coke, and we want to make sure they die of diabetes and not by police abuse.