Being the ones who opened the bottle, and then saw how dangerous the genie is, and shoved the cork right back in, we take it as our responsibility to guard the bottle against others who would open it.

If adult stem cells prove to be as useful as embryonic stem cells[1], then the only reason to harvest embryonic stem cells would be the sheer joy of killing unborn babies.

[1] It should be noted that adult stem cells have already proven extremely useful in treating many diseases, whereas embyonic stem cells have proven useful in treating exactly zero so far.