You just contradicted yourself- If a society saw personal glory-seeking at the expense of others to be the ultimate goal of life, then it would be moral to act in that way in that society. Morality, like scientific conclusions, changes to fit the new place and time it's in. I said as much and clearly you ignored it. Those that act outside of a moral landscape in that society are outcast or killed because that society as a whole stops existing when it's moral fiber decays. People bitch that America is a Christian nation because it hates fags. Well, yes. And acting in a moral way that helps these outcasts degrades that Christian America, thus is considered Amoral.It absolutely is. What you've offered is your own interpretation of morality, and if you told it to a norse warchief or a 17th century slaveholder, or a Mennonite laypreacher, they would laugh in your face because of how wrong they think you are. Not all morals originated around "this is best for society", there were societies that saw personal glory-seeking at the expense of others to be the ultimate goal of life, there were societies that considered the proliferation of dynasty to be the most noble and moral pursuit of man, and there were societies that willingly sought out their own death and destruction for the glory of God. Morality is very subjective.
Morals are entirely objective, that's the point. It's the society that is subjective and when you act in ways that aren't objective to keeping that society the way it is, that society ends. There is nothing hard about this concept. Cause and Effect.
If your society is based on eating meat and meat only, and one day someone eats plants and you don't shun them for breaking a moral taboo, then it's not the moral that changes, it's the society changing. The moral of eating meat only will stay the same regardless anything else and the rules formed around it as well, but if a society changes to the point where it's moral compass is lost, then it's not the same society anymore.