Dragon Age 2 and Mass Effect 2: The Conversation Wheel

[Eclectic Dreck]

Writing a new line of dialog is trivial.

Not really. When writing dialogue, you have to take into account who it is that is saying the line. What kind of character is currently speaking right now? Would it be in character for he or she to say this line? Would it be realistic for this character to be saying this line in the situation that's currently happening? Does this line fit the overall tone of the story being conveyed so far? Writing ain't a simple thing.

You are missing the entire point. All told, the effort required to write the line is trivial when you consider how much more effort is required to produce a voice over version of that same line as this would not only include the original effort of the writer, but also an actor, casting agent, directory, sound engineers and so forth.