An Unprofessional Approach
I have always regarded Oracle and the like as Business Prime Data systems where modelling and its maintenance have been essential to an ongoing successful business.
The problem for a lot of smaller Businesses is that they simply cannot afford a professional approach to database design and certainly will not pay a license for DB/Artisan or ER/Studio or see the need for such tools.
Compounding this is Microsoft's decision to push SQL Server to the desktop level whilst neglecting appropriate products like Microsoft Access. These SQL Server designs only have a physical model with limited metadata, if any, but they work at least in the short term.
However, the design degrades markedly when the DBA moves on and maintenance or new features need implementing. This is going to be a costly mistake for such Businesses in the long run.
Good DBA's with modelling skills are worth their weight in gold but rarely found.