Umm because it's a human being not a material possession. I thought this should be common sense to everyone
I think your getting utilitarianism confused with the evil s word. Not only are you talking about something unethical but now you want a governing entity comprised of people no more virtuous than those in this thread to tell someone what to do with their body.
I really hope your trolling and don't truly think like this.
Imagine the unplanned pregnancies and Soo true very unethical.