It also took quite a while for people to come up with the concept of universal human rights, we're still bad at overcoming tribalism, and basing morality on maj

It also took quite a while for people to come up with the concept of universal human rights, we're still bad at overcoming tribalism, and basing morality on majority vote isn't necessarily the best idea. That aside, you're right that I also do not assign equal moral standing to humans and nonhumans. However, that does not mean that the same arguments that make me reject culling humans don't also apply to other animals to some degree. I would argue the ethically most defensible approach would be nonlethal fertility regulation.