Just an FYI of the voice acting for bioware
DA2 have two voice actors Jo Wyatt & Nicholas Boulton
ME1,2 & 3 all have two voice actors, Jennifer Hale & Mark Meer
DA:I gave us four Harry Haden-paton, Alix Regan, Jon curry & Sumalee Montano This is the only title that gave 2 options per six all the other gave 1 option per six exactly like FO4.
Bethesda isn't adding voice to sell more copies. They have a vision and it isn't about catering to the wrong crowd which i laugh at because it assumes that it is a bad business choice to expand your fan base. The motivation behind the voiced protagonist was their desire to bring stronger narrative to their games. Mr. Howard stated that the have the data from skyrim on how people play their open world games and now they wanted to add a strong story without sacrificing the open world experience. That is their vision. "If you look at games today that are telling strong stories they all have a voiced protagonist." A quote from Mr. Howard. (might not be eactly word for word)
https://youtu.be/2KApp699WdE?t=2h22m27s
A recap.
They want to bring better stories to their games.
The examples in the industry of RPGs with strong stories all have a voiced protagonist.
Voiced protagonists do not hurt sales with the RPG crowd.
Voice protagonists are an industry standard.
There simply isn't any reason for them not to take this next step. It lines up with their artisitc vision and it won't hurt them finacially so why wouldn't they do it?
This all said if bethesda didn't have their current vision to bring strong story to their games then i think there would be far less insentive or reason for them to take this step. But this seems the most natual prgression for them. story is their weakest feature, at least thats is my opinion, and I think many people would agree, so it only makes sense for them to want to take this weakness and turn it into a strength. whcih natually leads them into the voice protagonist.
Bethesda has a very strong track record of making major changes to a Franchise and having pay off in sales as well..
FO3- Went to a first person perspective real time which cause a fecal storm of epic proportions All spelling the doom for the frachise and it was a huge success.
Skyrim - Streamlining this will ruin TES the game will fail and it was their best selling game ever. Apparently you actually don't need attributes to make varried characters and role play them.
FO4 - adds voice protagonist. i am pretty bloody sure this will go over like a lead balloon with a portion of their fans but will have zero impact on sales. I predict better sales than FO3 and a decent chance at better sales then Skyrim.
Bethesda has every reason to beleive the anti voice crowd will be wrong again given the fact that their vison is taken them from smaller studio to industry leader.