I guess it just comes down to different players wanting different things. Some of us want a total blank slate, no voice, no expressions, so we can imagine/insert whatever we want into those moments. And some of us want the character to feel a little more alive, to have a voice and expressions even if they might not be 100% under the player's control at all time.
Personally, I liked how DA2 handled it, where Hawke's reactions/expressions were dependent on 2 things: 1)Whatever dialogue option you chose. In these instances, you WERE choosing his expressions, because the tone/mood of the dialogue came with an expression that fit that tone. And 2)in cutscenes where you weren't actively controlling Hawke, his expressions/reactions were largely dependent on what type of Hawke you'd been playing-- diplomatic, charming/sarcastic, or aggressive. So in a sense, you HAD shaped the character, and the engine was just carrying on with the type of Hawke you'd been playing. Sure it wasn't perfect, but all in all, for me, those moments took me out of the narrative/out of the moment LESS than when I played my Warden (especially during romance stuff-- like wow, my Warden was a total cold fish. Not even a little smile when you tell someone how you feel about them? Creepy). It made the times my Warden DID have those couple of expressions feel really odd and out of place with the rest.
But again, it all just comes down to personal preference. I'm not going to be able to convince someone who hates not having 100% total player control that the way DA2 did it is best, and they aren't going to be able to convince me that it's a bad thing to sacrifice some control for the sake of playing a character who feels alive, who feels like they're really truly ENGAGING with the other characters.