Originally sacrifice meant something very different. As a rule, when people started sacrificing for things(like killing a dove for a deity) they did so for something. The closest thing we have today is many of the African diaspora religions(I sacrifice this cake, you *name of deity* give me a pony).
For me, that's the only way in which sacrifice makes sense. You are sacrificing for something. If anything, it is more like a merchantile exchange when you take the deities out of it.
Except in extremely rare cases, sacrifices that a person doesn't get anything out of tend to end in resentment(as the word sacrifice assumes that you are giving something that is valuable to you) and that is never a good place to be in a relationship.