If human life does not have intrinsic value, then you’re right. The only concerns would be pain, emotions, consciousness, and relationships. I believe, though, that human life does have intrinsic value—because God decided that it would.
Now I don’t believe Evolution; I think it is a seriously flawed theory, from a scientific perspective. But let’s assume for the sake of argument that Evolution really did happen. The progression of species through natural selection depends on genetics, mutations, breeding, etc. Over millions of years, species tend randomly to improve, responding to their environment and their genetic makeup.
If all that is true, then, the absolute worst thing we could do to our species—the most advanced life form—is kill individuals randomly. In my country alone, about 50 million babies have been aborted. What if one of those children contains genetic information that would help raise our species to the next Evolutionary level? Evolution depends on individual living to grow up, reproduce, and displace weaker members of the species. If millions of individuals are not allowed to reach adulthood (and therefore never reproduce) we are stifling the process of Evolution and working against the betterment of our species. Who knows how many Einsteins, or Hawkings, or Aristotles, or Churchills, or Jeffersons, or other potentially great minds and individuals have been eliminated through abortion? Who knows whether the person who would have found the cure fore cancer, or who would have perfected nuclear fusion, or would have done some other great thing, has been killed?