Yes and No

While I do think you should have a walled off area I am strongly of the opinion that every organsation should have a fully open pool database / test environment open to absolutely everyone as well this allows the talented to teach themselves and make mistakes.

Only then will you be able to develop the staff to a level where they have both technical competency of database management skills and the perspective of understanding the data.

I have seen too many companies that bunker the SQL Server knowledge and access resulting in the IT department having a lack of perspective on the tasks required by operations and operations having a lack of understanding of things like primary keys audit trails etc. This is also a recipe for excell hell. Where operations start developing whole processes in excell.

I think we need to encourage Dev Ops - its really in everyone's interest.