I actually fail to even understand how it can break immersion for someone if he/she does but if yes - I agree they could simply give you an option to turn it off
Some examples - your quiet rogue character has a raucous, overly fake and shrill voice. Your berserker barbarian has a clear and polite voice when you want him loud and crass. Any fake voices when you want your character to sound like a real person. Also the constipated sounding nonstop grunts whenever you get hit. Extremely immersion breaking when in stealth. This one not really dialogue related but still annoying.
I will only be happy with forced voices if we have the option to turn them off, rather sick of having to turn sound completely off in games.
That's another problem - custom protagonists showing emotional responses that are very theatrical and overacted, as well as completely unfitting (depending on the character - like squeamish drow).
Yes, this is a big problem. Will play with sound off if I am forced to (due to stupid sounding voices) but impossible to turn off stupid facial expressions.
Of course the Protagonist will speak. And SHOULD. Voice number 1 (male, for example) is excellent for multiple builds - especially Wizard Elves, Humans, Tieflings.
Well lucky you for having a voice you want to hear. I shall respond in a like manner to you. The Protagonist SHOULD NOT speak as it is immersion breaking.
On a more polite note, I think we can all be happy if the option is there for both voiced and silent. Since we already have silent and they are supposedly adding the voiced, it shouldn't be hard to do.