We should prefer cultural diversity over monoculture.
When we over-generalise and over-simplify, we tend to become bloody-minded and impatient. We want to say "The situation is like this; why don't we just do it this way. Simple!"
But the fact is that while we are all like fundamentally as human beings, we are also all unalike in our tastes, preferences and values.
If we are all equally enlightened in the same way, yes, we can say all agree to live life in the same way - like all our religious teachers.
But we are not. We are each wired up differently, because of our hormones, genes, upbringing, culture and the things we read and see. We also want to be different, and try very hard to be different. This is ego, but ego is what is keeping ordinary men and women and even children alive from day to day, as they search for their own uniqueness and niche in life, which gives them meaning.
Given such diversity, it will be a shame to set one set of values as the overarching set of values and impose that on everyone.
The First Emperor of China might have got the right approach in dealing with diversity - invent a commonality for the eyes, but leave everything else as they are but evolving around that commonly accepted value.
We should in fact encourage creativity and evolution for a diverse culture to blend into something new and unique. By fossiling one set of values and imposing it on everybody, we run the risk of making ourselves irrelevant to the modern world.