Walpknut
This ghoul has seen it all

You are aware that voice work costs money, right? have you ever played Mass Effect? They have a vocied protagonist so they have to cut down the dialogue options down to about 3 things you can tell a very limited number of NPCs and all of them with very similar reactions from said NPCs. Voiced dialogue on NPCs already cut down on the variety of responses from them (Compare NPCs in the first 2 Fallouts to the ones in New Vegas or any other old rpg to new rpgs).
Also the spirit of Fallout is being able to create your own character and have different experiences everytime you run it, being it from the tangible like Stats and dialogue choices but also on being able to make up it's personality and voice on your own, without having to be Troy Baker doing a gruff guy voice.
I'm well aware of that fact, but I don't see what the big deal is - I think a voice protagonist is great, as not only am I sure that Baker won't be the only available voice to choose from, but it will help the PC feel more like an actual person rather then a carcicature of a person like in all games prior; and I think that's an improvement myself.
As for the second part of your post, I think we have radically different views on what the core of Fallout is, to me it's the story, the atmosphere, the universe and all that coming together to create an immerse and unique game world.
Now you are adding multiple voices to choose, which cuts down dialogue variety even more.... Which again runs AGAINST the spirit of Fallout. If you want to have a defined protagonist, there is plent yof other games where that fits, but not in Fallout.