But if you go away from inheritance, then OO is even *more* messy. Relational offers a more consistent and more viewable way to relate a bunch of information together. Objects are mostly just glorified maps (dictionary arrays) of attributes, functions, and pointers. (Robert Martin calls them "jump tables".)

Tables make better building blocks than maps of pointers for most things. Relational has better theory behind it than networks of maps. Networks of maps are shanty towns with no solid, consistent rules and a lot of work to change. There is no Dr. Codd of maps so far either. Two different people are more likely to come up with the same/similar relational shema designs than the same network of maps to do the same thing.