I can't conceive that more than a very tiny minority imagine their characters down to so minute detail as to have a specific voice in mind. Objectively being mute is *much* more immersion-breaking in a world of sound. Especially when playing the protagonist the world reacts to and somewhat revolves around.
For me it isn't specifics, rather that voices don't fit or are overly fake. I would take mute any day over sitting there cringing and wishing the character would just shut up, then turning off voices (or sound) altogether. If you are playing a quiet type character and all the voices are shrill and obnoxious it can be rather jarring. Likewise if you are playing a loud and crass character but all the voices are polite sounding, it doesn't fit. For a game where we have the freedom to make anyone we want, I doubt they could have enough voices to please everyone so silent needs to be an option if they decide to go fully voiced. Even if it is just a separate sound slider for our characters in the menu.
They have a choice for 2 male, and 2 female voices. I am sure they could make a choice from that drop down as mute rather than say "screw you" to all the people that want voiced PC's.
