With a data-driven system, you basically end up with the data as a sort of intermediate code which is then interpreted by the "environment". The interpreter sti

With a data-driven system, you basically end up with the data as a sort of intermediate code which is then interpreted by the "environment". The interpreter still needs to support the domain objects that implement the required behaviours. If you keep extending such a system until it meets all the requirements, you end up with yet another programming language and interpreter. A far more practical approach is to have clearly demarcated, library of reusable domain specific objects which are then assembled as required. Thus the majority of the functionality (the 80%) ends up being written in a sort of embedded domain specific language.