... terrible voice acting is worse than having none at all.
I'm inclined to agree with that. As both a fairly prolific user of player-made mods elsewhere and a creator of the same myself, voice acting is always the weak link as it's probably the hardest part to do well. It's a very specific talent, and probably one of the rarest, and then there's the aspect of actually recording it properly: a poor recording complete with background noise sounds
awful.
I'm probably coming across as sounding overly negative, but voice acting is just so hard to actually get right and can absolutely ruin a mod, and by extension the game it belongs to. Much better to have a dialogue system that supports both voice and text as we have at the moment, I think.
I agree with this. Sure, if you get Patrick Stewart and half a dozen other equally talented thespians to act out your totally brilliant script that took you five years to perfect, voice acting is good. But half baked it can be crigeworthy, your own imagination works better.
The other big issue is expense and QA constraints. Once you've cut the dialogs it's really hard and prohibitively expensive to edit them to fix bugs, so you have to design the game to minimise possible bugs (usually by simplifying the plot lines so they can't go wrong) and in general vast chunks of the budget get sunk in doing the voice acting production.
Which means less game content and simpler game content, pure and simple. DoS is long, involved and (relatively) difficult because without voice acting it *could* be long, involved and difficult. Note that the length of DoS is not achieved by spamming copy/paste meaningless boring kill this/fetch that side quests into a relatively short story line (like many other games I could mention) but with real content. That it is a text based game is one of the main reasons they could do that.
Voice acting? No thanks! Just give something like Dos, please, and I'll be very happy.