>>abstra+Y2
And I recall the last time I looked at the source (when it was released with Arc), it didn't use a database either. All the data is stored as files.
>>spoile+S5
Why should it be? You can get a long long way by treating the filesystem as a database. The first engineers at Amazon used the same technique a lot, as do I.
>>kansfa+S6
Just as one example, I think you could make a fairly convincing case that the official version of git uses a "filesystem as a database" system with great success.
I doubt it would be improved by using something more "proper".