> What makes you so sure about that? What if the context is "I hate scientists...they keep proving me wrong". Is that a show of hatred or a tongue-in-cheek show of respect?

You are correct, I didn't consider this, so there at least two problems with deciding what is hateful: (1) is the expression insincere?, (2) if it is sincere, is the hate justified?

This is of course assuming such a machine can be designed to obtain the correct meaning of words in every case, which I think is impossible or close to it. Language is ambiguous, some languages more than others.