Have we properly defined the site? No.
Are we supposed to do that in the private or public beta? I have no idea.
I'd say that the change from 'Database Professionals' to 'Database Administrators' caused the problem -- they have siginificantly different boundaries, and people signed up for something that's not what the site opened as.
I'd personally like to throw it open to the rest of the public to see what their opinion in the scope of the site should be, but it's possible that we might end up self-selecting by advertising as 'Database Administrators' and not get as diverse of a population, and so taint the surveying of what's on/off topic.