It's just not practical to spend that much effort. Technically anyone can spend a million hours making an all new look for a 2D engine but no one ever will. And if you can't even accomplish that may as well forget about modding the dialog and quests.
First, the dialogue and quest scripting is completely different from the art assets. It is entirely possible to have the skills to do dialogue and quests without having the skills to make new art.
That's always a bitch in any game, and if you can't make even minor changes to the looks no one is going to bother.
You are arguing that there is no point in making a mod if it doesn't have new artwork?
Just go to fan made fallout's old boards and see how moddable 2D games are.
Good choice. I was
slightly involved with FMF so I do have some knowledge on how the modding of that went. And our problem was never artwork - I think most of our artists were working with 2D renders of 3D models, but getting that art into the game was never a problem with (there are only two that I remember that had significant issues - one was a palette issue that required the artist to regenerate a slightly different pic and the other was a sprite-size and overlap issue that was handled by a mix of sprite cutting and object flag settings.). The problem with FMF was mainly contributer dedication and time effort and was focused in two main areas:
A) Writing - We had some good writers, but there was alot to do and there were not enough editors and reviewers for the writers to get timely feedback.
B) Scripting - We had a small pool of scripters and they tended to disappear or not spend the time needed to get the assets into the game (The latter was the category I fell into, for various reasons).
On a side note, one of the big pains we had with the engine was the amount of game logic that was hardcoded into the engine - fun to figure out, but a pain to replace across the different variations of the engine. Mapping was a pain, but not nearly as big a barrier to our work as the two items I listed above.
DU could (but probably doesn't want to remember it in order to) expand on that or correct me if I misspoke, but Art-related issues were probably the
least of our problems with FMF. If one of the artists can speak to it, they can comment on what problems they had with making art, but whatever they were, our artists handled most of them well enough to be invisible to the rest of us.
Or look at arcanum. There's a tile based editor but it takes forever to make a location, takes ten times forever to make a character, ten times that a character with all new weapons, and then you still need to make quests and stuff. Aside from weapons rebalancing mod there's not one mod worth bothering with even though some people put a ton of effort into it.
Can't speak to Arcanum - never did any work on that one. Your argument is still that modding is a pain and there aren't good mods. You haven't given any evidence that the reason for this is because they were 2D.