Why? Well, if you care so much about the unborn ( = potential people, of whom there are infinitely many), then why aren't you eagerly campaigning for the immediate colonization of the solar system, followed by the galaxy? Remember, there are always more potential people left to be realized, and the best way of realizing them is by continually increasing the rate at which new people come into existence.

'Unborn' does not equal 'potential people'. I see little point in trying to exhaustively explore the space of potential people. But given that there will be people coming after us, I fail to see the purpose in extending the lives of this generation at their expense.