In my opinion all morality is subjective, even the moral standards of any deity or deities that exist are subjective.
We forbid murder because the vast majority of people wish to live long lives without fear of dying, but it is still a subjective value even if held by 99.9 percent of people. A potential or actual serial killer who loves to kill for fun may disagree and think murder should be okay and there is no true objective standard to tell him he is wrong. The vast mass of people not wanting murder, form a powerblock so great, that they destroy or contain the desires of serial killers within themselves. And that is really all that is happening nothing of a true moral nature.
Two hundred years ago it was considered moral for a man to physically discipline his wife for any petty thing. If it is wrong for a man to physically discipline his wife for any petty thing now it always was, even if everyone thought it was okay and vice versa. If it was okay back then then it is okay now even if everyone thinks its wrong
Up until the last part of the 1800's slavery was considered just fine morally by many people in the world. If slavery is wrong it always was. If it was right back then it is right now and so forth.
