Using your own arguement, abortion is a good bit worse than a group of cultists moving into town and supporting the public execution of adulterers.
After all, the people being executed would be entitled to a bullet or a needle instead of being scalded by salt water or being ripped to pieces with forceps.
And further, the people being executed would be at least guilty of a crime instead of being innocent.
And lastly, a guilty person would have a chance to fight back or flee, unlike the babe in the womb who has no refuge to find safety in.
In general, I find myself agreeing with you, but the deliberately sloppy thinking involved in accepting abortion is repellent.