Well, if I believed Adam & Eve literally, you would have a point.
How about the zygote inside any woman during the flood. Any newborn first born sons in Egypt. You can say, well... we all are sinners so it's ok for God to murder babies, but I think God is better than that.
I think you have to come around your circular logic if I may make a constructive criticism. Because the Bible says so, is an end to all argument. If you accept that a fetus in a woman's stomach is an evil sinner, you might believe that God is justified in zapping it.
Were all the butterflies save for two sinners? Were all the begonias sinners? I could punish my kid by killing him for sassing me, as the old testament suggests, but why would roasting his pets as well be justified?
If you believe that God gets angry, jealous, hurt, you abscribe to him human emotions that are petty. God is not petty. I do not believe any more that God would punish the innocent, and yes I dare say those who have not had a chance to sin yet, still should be offered their chance before being zapped.
Noah is a justification for abortion when it comes right down to it. The parents were sinners, the baby would be a sinner, might as well kill them all. If you are a woman who has sex with a bad person, do what God did... drown your baby like the mother in Texas.
Yes, I absolutely reject a theology that says God would kill unborn babies for the sins of their parents, or the sins of their future. It isn't just, and I don't accept it.
That states your position more accurately.
Man cannot make up his own version of God...like you seem to want to do, at best.
"God is God, and I am not"
Steven Curtis Chapman