Yali’s question is important to us today largely because it can have a serious impact on how we think about differences between various types of people. Specifically, the answer to the question could affect our racial attitudes.
As Diamond discusses in the Prologue, many people tend to think that Europeans came to dominate the world because they are racially or, at the very least, culturally superior to people of other races. If people believe this, it helps to justify racism. If, by contrast, we accept Diamond’s answer to Yali’s question, we should be less likely to have racist attitudes. We should understand that the European dominance of the world was due to geographical factors that were completely outside of the control of any human beings. If we take Diamond seriously, we have no reason to believe that Europeans were any better than Africans or Australian Aborigines because we know that the Europeans benefitted from things like the abundance of domesticable plants and animals in Eurasia.
Since issues of race are very important to us today, Yali’s question can be important to us even though it is a question about the past.