At the risk of sounding a bit abstract - thought I'd ask a meta question about meta.
Why do we need meta.dba, rather than simply meta,se?
Because this site-meta is for the specific meta-workings of this particular site. Note our questions here such as the direction of this site, the particular closings on this site, etc. We need to keep some things local to this site, and this is the place for discussions of such things.
Additionally, there is a way to escalate bugs/feature-requests from this site-meta to meta.se, which I assume is part of why you're asking. Meaning, if you see an engine bug, report it here, if it happened on this SE site. Often this is the best place to repro it, so the best place to figure out a fix.