Morality and Subjectivity

No, it woudln't.However, it is a matter of self interest.If you feel free to murder someone, then others feel free to murder you.So, as a matter of self defense, a social contract developed for the soceity. From a simplistic point of view the contract is.You don't kill anybody in our socieity.. and we will , as a group, try to protect you from those who will try to do that. You violate that agreement, we (as a group), will come after you and eliminate a threat to us (as a group)