1) because it implies that one day they might be it favour of bringing them back with the right technology etc
2) because you want to convince people of important moral principles. I don't want you to not beat your wife because you'll get caught, but because it's inherently wrong.
Certainly fodder for ongoing discussion but I think it’s important to prioritize goals.
Alignment on public policy decisions allows for more degrees of freedom in underlying philosophical differences than attempts to align on the philosophical primitives themselves. It also achieves an immediate goal.
Plus if you are engaging in conversation in a good faith attempt to understand and be understood, you have to allow for the case that your views are moderated or changed as well.
(The distance you feel from that right now is approximately the same I feel in the opposite direction.)
2) because you want to convince people of important moral principles. I don't want you to not beat your wife because you'll get caught, but because it's inherently wrong.