If we were to live alone by ourselves in isolation in the middle of nowhere, we can practically do anything we like and we will not bother anyone else. Except probably ourselves only because, maybe, we want to live long - but how long is long we would not know if we were to be all alone - or even healthily, if we know what it is to be healthy if we were to be all alone. There will be no morality and we will have complete rights.
Morality is an issue that comes up when we try to live together in peace and harmony with each other. We try not to offend others nor do we want others to offend us. That is why all communities have their own sets of manners and courtesies and customs. The social rules are usually not made up artificially but after many years of trial and error and the consent of generation after generation.
A community will develop along a strict code of conduct when somebody decides to put down all the commonly acknowledged rules on paper (or carved in stone). This strict code of conduct is likely to be biased, religiously or politically. It will be followed until it reaches its golden age. This happens in the high societies of India, China, Europe and even the more ancient tribal societies of Africa, South America and even Asia.
In their golden age, the societies stagnates because they could not change anymore. Everything has become so rigid that every deviation is immediately eliminated. The form of social manners is unchanging.
This stagnation can go on for a long time, but eventually it will break down. The gene pool deteriorates and society degenerates. Or, new thinking is introduced through interactions with different societies. New ideas are formed that either challenge the existing orthodoxy or new ideas that no one has ever thought of before. The line between right and wrong becomes thinner and blurrier and sometimes disappears completely. As this happens, there is less compulsion from the moral police and more exertions of individual rights.
In modern societies, it is the sacred right of individuals to defend common sense and fight against the tyranny of the ignorant. The ignorant are usually self-serving persons who exercise the little power that they have to the great annoyance and irritation of everyone else whom they can bully. They do not know what they are doing but they wish others to know that they are important because they have this power, small though it may be.
Ignorance is everywhere and the only solution is honesty, integrity, and common sense which all together comes under the word "wisdom".