• definitely an issue of use case, I will agree. 
    My brain boggles at even how I would find a data situation that would require much past 4th normal form, and even that tends to cause mental explosions. Experience levels of the DBA and Architect also affect the final solution. I've met a few folks fresh out of training hell-bent on maximum normalization, when truthfully, a completely de-normalized table is the fastest and most optimal solution. As for foreign keys, nice, handy, and very useful, and have saved my butt several times, but sometimes, based on business logic, you can find a situation where enforcing integrity at the application level is a far better control than relying on the underlying database architecture methods.

    This is where the DBA, Data Architect (if available), and development team, and the stakeholder need to work together to arrive at the most optimal solution.

    As always, in this industry, the answer comes back to "It depends."

    Luther