But yeah no, I'm really happy I moved my text box from the right-hand Disco-style orientation because it's a really shitty way to read text. I tried it for one short game and ended up hating it. Like who the fuck thought that was a good idea? Centralized text boxes are better.
My guess is the reasons for it are twofold:
1) When text is centralized you have effectively less space to use before you start obscuring characters who are talking and so text is also smaller as a result. You really don't want that in a game with a lot of text.
2) Text box is located on the right side, because majority of the people are right-handed and that's where they turn their eyes to first.
I agree with the first point; second point is where problems arise for DE, as it should be actually opposite for text-based game made for western countries that are reading from the left to the right.
When you design application organized in two columns, content(most important part) is on the left/center, given the most important place of the screen, and rest of tools and info are moved to the right or edges of the screen.
Lots of classic games have this organization of the screen, like HoMM3, Ultima and it works.
App layouts all changed with mobile phones and catering to RTL reading part of world, but that is it in the nutshell.
DE, by how it presents its information, should be more alike to the VN or Text Adventures (Interactive Fiction, as they are rechristened later) with text at the lower part of the screen, with graphics above - or even in the style of the subtitles, with transparent background.
This layout could work, if DE text isn't self-important, unredacted verbal diarrhea that goes on, and on, and on; and there are 4-6 choices based on your senses.
Text box would take half of the screen if you put it on the bottom, so ZA/UM put it on the right.
This results in player spending most of the time reading on the smaller, right side of the screen, while characters loop their talk/idle animations on the most important part of the screen.
Eccentric painting-style graphics are just a nuisance; you try not to get distracted by it from reading and understanding text and plot of the game.
This is unnatural, and you feel growing irritation after a while.
TL;DR - DE is flawed from the core in the way it presents its gameplay and content - which is also flawed by not removing extraneous parts in pure fucking hubris.
Every game that follows DE design anti-pattern will have none of novelty that made it successful and all the audience repelling faults.