I am not sure DBA skills are necessary. You might be thinking, "Um, you are a DBA and your livelihood depends upon it!" Let me explain.
DBAs are necessary so long you own a RDBMS. Does this mean you need a full-time DBA? No, but you will at some point need the skills a DBA has. Many times a DBA is called in after the developers who built the system are all out of ideas on how to fix it. Developers are seen by the unknowing as THE all knowing entities. They make shiny new applications that enable me to click a button and have the world succumb to my will. The problem is this lumps all parts of the application under their domain: front-end, middle tier, back-end.