It's considered to be "`exotic`, `academic`, `never used in practice`, etc., etc." because for some reason most of the DB people believe that 1 relation in the data model should map to exactly 1 table/B-tree in the database — and of course, the 6NF then becomes ridiculous.

But the relational model from the very beginning was about abstracting the concerns about how, exactly, those relaltions are supposed to be implemented/stored, and concentrating more on the conceptual API for querying.

A good engineer will design normal form data and use objects with an orm that represent that. Possibly even abstracting further in order to have good business models. Bad engineers try to shoe horn an object into a table.