We've established that one can lead to a child and the other can't. The question that this debate is around is whether the inability to naturally conceive means you are prohibited from adopting a child.
I say no it shouldn't. That doesn't extend to everyone being able to own a child as if they were a commodity, it just means that your ability to conceive isn't the judge. Your ability to raise, support and love a child is the only judgement.
So, is ability to naturally conceive an absolute barrier to being a parent (with all the options available today to facilitate this)? If you can't conceive naturally, you are not permitted to be a parent?
With Gay adoption my stance is I'm just not sure either way and until I'm convinced something is right then I don't believe in change for the sake of change.