Why sex is taboo

According to all people around the world sex must been legalized between 2 people. That is this for centuries even before all prophets, even before first philosophers, people liked sex but they scared sex.

Because people were a sort of animal and they could do sex free, like cats or dogs or birds. But since they evaluated to humanity they resist to being like cats or dogs or birds. Because when they evaluated to humanity they became social sort and doing sex free in streets and with everybody is contrarian social thinking humanity. And humanity made taboos for being different from other animals.

Sex taboos are ways which for escaping animalistic nature and freedom.