I'm not sure Data Architects need to have a background as a DBA. In fact, I've blogged elsewhere that I think there's a sort of Mason-Dixon Line in IT that keeps people happy on either the logical (business requirements) or physical (build and support) areas, but rarely both. Sure, people work on both sides, I but I think they are drawn to one side of the line or the other.
I do think that architect/modelers need to have a certain level of literacy in order to participate in design efforts. And I think people on the physical side (devs, DBAs, etc.) should understand the need for integration, data quality, business requirements, etc to make the right calls when it comes to tuning and support.