I agree — from the outside it would seem like mastery of facts ought to be simpler than handling the nuances of style, right?
But it turns out that semantics are freakin’ hard for machines — because it hinges on the understanding of concepts, and we don’t yet know how to get a machine to absorb those concepts on its own. Merely mimicking style, on the other hand, turns out to involve a lot of pattern recognition and statistics, which machines are great at ….