Sacrificial lamb support gem doesn't work (and shouldn't even have to exist)

Sacrificial lamb support gem doesn't work at all, game still makes me sacrifice random minions all the time. The fact that this support gem even exists is a bigger issue though. Why is that a support gem? Why is this not just a setting in the UI? Why do we need to use a precious support gem slot to make up for game's poor targeting system and lack of basic settings?