You don't need moral realism to arrive at a set of mutually agreed upon moral values. You don't have to agree with your friends on what's the best food in the world is in order to choose a place to have dinner.
There is an argument that you don't like the process by which the moral values were arrived to, but that's hardly a reason to indulge in moral nihilism.
There is an argument that you don't like the process by which the moral values were arrived to, but that's hardly a reason to indulge in moral nihilism.