The order had to be hidden at first because we had no idea how we could properly contain mass hysteria when we actually decided to start coming up with certain decisions that could lead to disagreements against us. The order is not worried about human outcries because we fear them. The truth is that we need humans to keep this planet running smoothly. We cannot afford to have to get rid of all of them or a large portion of the population.
This is the reason why the order is still hidden now too but the disguise is brilliantly out in the open and poses as fictional to millions of people. Those who are clueless about what we do are always going to find it hard to understand the kind of power that we have and we would rather have them think that we don’t exist.