There is a lot of data-driven stuff in Kaduria. However even such a good idea can be ruined with poor design. I wouldn't call it a failure in this case, but there is data that doesn't have a clear structure. Recently I got an idea to create styles for terrain tiles so each type of wall could be a part of some style (dwarven, ancient, elven, etc.). The style is a great target for a data-driven type, because then you could retrieve all sorts of objects that mostly belong to that style.
The problem is that style class would override other data already set up for level themes. It's a layer of data on top of existing data. Another problem is to determine how much and where each class or system is used. The style can't be same as level theme, in fact there could be several styles in one level.
I've had similar problems with main type of object data classes. It reduces the amount of data, but then you have two classes to maintain, with kind of dialog between classes that can be difficult to create.
I think styles is something that is required after all, which is yet another example of undefined design that should have been there.