The reason lots of people dont read, or even don't listen to all the dialogues, is because most of them are shit. They are uninspired and boring. Often I dont finish reading it all because of that. And only a few years ago I played and finished Planescape:Torment. Which has barely anything voiced, and TONS of dialogue, but still I read it all and was sucked in. I even wanted to know more and more.
I wouldnt mind the dialogue to be voiced, BUT, voice overs are expensive, very. This is probably one of the reasons that RPG's these days only have the "bare" minimum of dialogue. (in comparison to +-y2000 RPG's, like theBlackDragon showed in his comparison image.).
So it is mostly a choice between
A. lots and extensive quests, multiple solutions, ...
B. all voiced, but quests can only be done in 1 or 2 ways, way less quests, ...
So then just give me option A.
