When people of high intelligence and motivation voluntarily remove themselves from the gene pool without reproducing, they are decreasing the commonality of that trait, effectively lowering the average intelligence of future generations. In addition, highly capable and motivated people tend to pass on those traits to their offspring through parenting, reducing the commonality of that personality trait as well.

In other words, when intelligent, capable, motivated people eschew reproduction completely, they are actually contributing to the mediocrity of the human race. This makes future advances progressively slower and slower as the genes for intelligence and the ethic of motivation becomes rarer and rarer. I assert that the world won't be better for future generations unless the future generations are better.