Because it's a statistical process generating one part of a word at a time. It probably isn't even generating "surprise". It might be generating "sur", then "prise" then "!"

Because it has no mind, no cognition, and nothing to "feel" with. Don't mistake programmatic mimicry for intention. That's just your own linguistic-forward primate cognition being fooled by the linguistic signals the training set and prompt are making the AI emit.