i dont really get the point but i'm also tired so wtf. Is the problem you want voice acting or is it just because it's plain text without some mannerisms like slovenly speech?
If its the mannerisms thing the reason is most likely to keep things plain and simple to read. Grizz is australian and some people had problems with the text early on so he changed it all to american. Putting regional colloquialisms into the story would just make it harder for people to follow or understand and in a murder mystery that you need to solve that can be alienating.