What's your opinion on people using "literally" in a way that means "figuratively"? Normally, I'm not a stickler about this kind of stuff... But now when people say "literally" ('Man, I've literally been listening to this album non-stop all week') I don't know if that's what they actually mean.
words change. that's what they do. you wouldn't believe what some of the words we use commonly today were 'originally' 'supposed' to mean. in fact, i think the word 'literally' has certainly been through many transformations before this one. so your undertanding of it to mean 'exactly' is surely just one stop along a multi-century train ride of language transformation