Those uncivilized societies were rightfully left to the dustbin of history -- they embody the nihilism I am referring to.
It's like when a people revolt against their government. This is wrong to do, unless they win; then it was always correct.
There are many people who succeeded in our time who are viewed by many rational people as being very wrong. Corrupt Russian oligarchs, policy-anulling health insurance bosses, Bitcoin thieves...
Having the power, or cunning, to get away with something doesn't make it right to do so!
But as a society? Within its own framework? Sure it does. Another society can view it as wrong, and maybe they will go to war over it - what they used to call an 'appeal to God.' The ultimate winner is the right one.
Why do you think what's 'right' can change over time?