GIS "Data Models"

Most IT professionals have some expectation, having received a basic education on relational data modelling, that a model for a medium sized problem might look like this:

Why is it, then, that production GIS data flows so consistently produce models that look like this:

What is wrong with us?!?? I bring up this rant only because I was just told that some users find the PostgreSQL 1600 column limit constraining since it makes it hard to import the Esri census data, which are “modelled” into tables that are presumably wider than they are long.