Theistic morality

[Purple Rabbit]

Indeed it would be and historically it has been in large parts of the world. See the example above.

That seems to demonstrate a flaw in your moral system.

Nope.

You can't condemn the Taliban for oppressing women, as that's the norm in their culture.

Oh, I can condemn those acts from within my moral view just as you can from your allegedly objective moral framework. The only difference would be that you claim absoluteness, IOW you're right and the others are wrong and that's an absolute. There you are in Afghanistan face to face with the Taliban. Would it help you in any way that you claim the absolute? Like say the crusaders in the middle east? If you condemn those acts you are doing that from within your own moral framework, just like me. That's exactly what's happening in the real world all the time. But you have to realize that condemning as such is not a goal but a means. Condemning is a rather ineffective means to change moral views. It IMO is more effective to not attack values but the rationale behind it based on informed reasoning and to try to achieve sharing of moral goals.

Neither can anyone change society's moral view, because there is no standard to which that person can appeal to change others' minds, if morality is just society's view; they will necessarily be wrong, because they'll be arguing against the majority view. Therefore, William Wilberforce was technically morally wrong, until society's view changed. Also, moral progress becomes completely meaningless, as I've said, because no one society can be called better than another.v

Non sequitur. It does not follow from an absence of an objective moral standard that moral standards cannot influence each other or cannot be changed. Moral standards change because they influence each other, moral rationale is (re)examined in the process and goals are reformulated as a result of trading and negotiating processes (if you grant me this I'll grant you that). The claim of an absolute standard is what inhibits moral change more than anything. That is the claim of traditional christianity, that is the claim of Judaism, that is the claim of muslim fundamentalism, that is the claim of any totalitarian state. Stating the immutable is what constitutes fundamentalistic dogma and inhibits moral evolution.