Possibly the most important skill for a DBA is the command of T-SQL and their ability to test, debug, and optimize performances of db designs and SQL code. My experience taught me that developers typically do not possess the best skills and understanding of this. While it is true that getting a db system out of the box and up and running can be accomplished without a DBA. From there on, it depends on how good you want your system to be. Goes back to the earlier discussions of how good is good enough.