It's ideological purity which has no place in the real world. Fully normalised structures are slow, dangerous and place expensive and frustrating burdens on up

It's ideological purity which has no place in the real world. Fully normalised structures are slow, dangerous and place expensive and frustrating burdens on upstream users reducing the amount of value that can be extracted from the data. I've been working around data for 20+ years and not once seen a dataset where tables could be blindly joined without some conditions. In these situations it can be better to just pre-join them so the business logic is captured. You want to be pragmatic and have a healthy and constructive mix.