Are you saying it's actually good to abuse people because it makes the gene pool stronger in some abstract way?
Outside of a few wealthy democratic enclaves, the world is largely a place where the rule of law means the rule of the strongest, where human rights don't exist, and where everything and everyone can be bought for the right price. This includes international waters.
I think he is just wondering why we don't consider the impact of immigration on genetic diversity. If we have nations that have huge immigrant populations and nations that have huge numbers migrating away from them it would have an interesting impact on genetic diversity. There are a range of traits that influence whether someone would migrate from a place or stay where they were born. I don't think pondering the effects of that requires a psychiatrist.