So the objective reality you claim morality is grounded in simply doesn’t exist. All you’ve done is kicked the argument from morality having a subjective component to morality being from an objective higher power …
Well, no actually. Your argument is that because individuals disagree on moral values, these must, therefore, be subjective.
Scientists disagree on lots of things, from global warming to quantum mechanics, that doesn’t imply that the observable world is purely subjective. It does imply that human beings do not have complete access to information about it and that we lack to some degree the capacity to use the information we do have to completely explain the observable world. Mere lack of agreement doesn’t prove subjectivity.
If you want to begin by asserting subjectivity, you undermine completely the possibility of establishing, determining, or discovering whether objective and real grounds for morality exist in the first place.
The most reasonable course of inquiry would be to not assume either position but continue to seek possible objective and subjective components of morality until the role of both become clear. To rule one of those out before completely understanding the nature of the moral landscape is putting the cart before the horse.
It is entirely possible, for example, that there are both objective and subjective components to morality – that some actions are universally proscribed or prescribed while some actions are only individually or relatively problematic because of how they negatively impact a specific moral agent within a specified context.
To merely assert that morality just is subjective is a morally defective position primarily because you are assuming that universally obligatory moral acts do not exist. By merely asserting moral relativism you are de facto making morality itself a matter of individual veto. In other words, you are simply asserting that the individual has the superseding moral right to decide whether they will or will not be moral at all and the extent to which they will be. Morality cannot, then, be a matter of obligation or responsibility but of pure personal choice.
Humans would not be moral agents, but moral authors with the field wide open to all moral determinations because there would be no higher moral authority than the individual human will.
As soon as you go there, how do you morally sanction murder, rape or child abuse? The murderer, rapist or child abuser has just as legitimate a personal veto regarding all of his behaviours than you do in declaring morality purely a subjective matter to begin with. You may as well throw out all moral determinations because these then become matters purely of force by imposition. You can’t, then, appeal to any principled ethical discussion, morality reduces to whatever rules the party wielding power decides. You further jettison all recourse to any discussion about what is good or bad, morally speaking. These terms become mere placeholders for whatever those with most power decide to impose upon everyone else. Fun times.