I would have to disagree. I believe that some cultures are self-evidently superior to others. For instance, there's the culture of Afganistan under the Taliban, where schoolgirls were burned for daring to learn to read. There's are or have been cultures that were built on conquest and slavery, horrific exploitation of the masses by the rulers, denigration of women into virtual slavery, a general devaluation of life, disdain for education and science and progress, and so on.
Some cultures are better at promoting the greatest good for the greatest number; some suck at it. Some cultures tolerate and even promote constant petty thievery, quasi-random acts of severe violence, unbelieveably harsh punishments for relatively minor offenses, pandemic corruption, and institutional inequality.
In brief, some cultures are just plain ****ed up.
Others plainly and clearly promote productivity, prosperity, peace, honesty, ethics, virtue and benevolence far more so than most.
Another way of putting it is that some cultures are based on the best-possible solution to the Prisoner's Dilemma, and others are based on far less than optimal solutions.