even to ride with your (perhaps arbitrary) definition of a being, what is it exactly about "potentiality" that divorces it from moral obligation?Potentially is the main word here. It's not a being, it's something that will potentially become a being. And since it isn't a being, why am I obliged to let it become one, and give birth to it?
What to speak of moral obligation, even legal courts recognize potentiality as a feasible reason for damages (for instance if you are injured and cannot progress in employment as you could potentially otherwise, you can be awarded financial reimbursement)