That doesn't make sense to me either. There are ways you could make it make sense (i.e. you decide that even though it isn't murder of an individual, we so cherish parents' hopes for their future child than we treat it as if it were an individual--not for the fetus' sake but for its parents'), but simply declaring fetuses to be individuals in one law and not in another makes no sense to me.
However, that one area of law succumbs to superstition or internal contradiction does not mean that we should encourage others to do so also.
The rest of your post seems to misunderstand the issue. You hunt witches to prevent them from cursing people, of course. Curses ruin people's lives, possibly even killing them. You don't kill witches for fun--you kill them because it's a moral imperative, based on the wickedness and harm they spread through their dark magic. You cannot suffer a witch to live because witches harm and kill (not directly, but through sickness and accident). We have the death penalty for physical murderers. Why should it be any different for those who use magic to murder?
Except the critical question is: are these beliefs about witches in accord with reality?
I'm not going to do the point about blacks because of how incredibly offensive it would sound, but again, you have the premise totally wrong.
So, it just seems like you're again telling me that we have to take people's fantasies as seriously as we do realities. Which, to me, just sounds like we should burn witches as long as enough people agree that they're witches.
You said, "it is not a natural fact that a developing tissue needs to become an individual before it's worth protecting". No it isn't, which is why I made an argument about why that's the thing to look for. You responded by saying...nothing. You just totally ignored the argument, and re-stated your original position!