@indemnifyme - I see what you're saying, but I think there are a lot of advantages to using a centralized database management system. As you said, it is faster.
However, I think the fact that it's easier to secure physically is a major advantage. A database is a physical object, so it can be stolen or damaged. And then the contents of the database will be damaged too. It seems like it would make a lot more sense to just have to worry about one database instead of several.