We all can agree that a voiced protagonist does change things a lot, but to say it is a mistake? Maybe yes, maybe no. MEANING, unless you have already played the game, how do you know? PLEASE TELL US. Oh, playing other games like Mass Effect has already determined it. Really? Mass Effect is with Bioware, not Bethesda, thus let us decide Bethesda has failed (or not) when we play it when it is available.
OT: The other part for voiced protagonist is dialogue lines are cut, thus fail. Really? I do agree dialogue are cut a bit, but how do you know before proclaiming a "fail"? Is quantity more important than quality? Or vice versa? Hell I don't know, yet because less lines for protagonist vs FO:NV, maybe FO3, means automatic fail? For me I do not know until I play the game.
Thing of it is, unless you've played the game already, do not let concerns triumph the game itself until release. If you think it is a disappointment already, then do not purchase it. You do have a right to voice an opinion, but do make your statement become fact at this stage. There is fear going on, but perception now is almost different when we play the game WHEN it comes out. If you have doubt, then do not pre-pay/buy it until reviews comes out then. Yet, it seems, this option unavailable.