We're willing to put up with quite a lot in games. Playing Dragon Age just now, I clicked on ten different soldiers who all said, "Maker bless you, my Lady." Hmmm. We're willing to trust that these characters have nothing more to say. I find this hard to believe.
I do believe in technical restraints. Anyone who's played Oblivion would have a hard time not believing, after the voices of the beggars changed so much. I'm told this was because they ran out of room for the audio on the DVD. What a terrible fate for any character, let alone a city-bound beggar with five different accents.
But, and this is something I remember from long ago, before games became full of sound and noise (two very different things) - what ever happened to playing the same sound byte and replacing all that talking with text? Baldur's Gate did so to great effect, and Aion does it as well today. That way, the writers can write without having to worry about pesky technical limitations. They can write what they want, as long as it will fit in the character's invisible speech bubble. And they can create a richer world, being no longer tied to recording schedules and size constraints.
This audio-only-dialogue thing began when conversations became more cinematic. When talking to someone was more than just clicking on text boxes over the same old isometric view. Then again, Fallout managed to have half-spoken cinematic conversations, with a couple of lines spoken, and a couple of lines not. It became immaterial that some had audio and others were without - it seemed only natural, somehow. The things that they spoke were important. The things that they didn't, were not. The use of audio, in that sense, was to direct the player to pay attention, as well as to evoke emotion. I don't see that as a bad thing.
Still, in these days of $20 million budgets for movie-game tie-ins, I guess recording only selected lines or selected characters just won't cut it. But even those characters, who are only called 'Soldier', and only speak one line each, repeated ad infinitum because you can't tell who's who - surely they could have something more to say? Surely they could have names, too? The intentional lack of a name signifies someone you don't need to talk to, but is that really a world view we should be promoting? As a writer, I like to think everyone has a story to tell. I don't see why games should be any different.
I've worked in games. I know how much writing sandbox dialogue can suck. But it can also be one of the few places where you can let your guard down and have some fun. Somehow I feel today's game writers are being cheated of that outlet. Then again, it's a brilliant way to ruin the tone of your own game, if you're not careful. So perhaps it's a lore-based constraint, rather than a technical one, but has the added bonus of saving the programming team a bunch of time hooking one-line-of-dialogue-X up to met-once-in-a-playthrough-Y.
That's one of the things that I do vastly prefer about Aion. Every NPC has a name, and something to say. They may not have fancy recorded dialogue, but they're there, they're interesting, and they're unique. I don't care if they don't talk. I get tired of listening to people yabber on anyway. Bring back the silence, I think, at least for unimportant exchanges. It made us read, and it made us imagine, and it kept out social skills honed by making us guess. Many a time has come and gone where a character has said something in a different way than I've read it. Let me tell my story, though my own inflections, and leave the recorded dialogue for the important people. I'll thank you. I promise.