Oracle's had a philosophy for a while now that, "We're the database company; so anytime our software has to interact with any data, for any reason, we'll have it create an Oracle database for the purpose."
The trouble is, an Oracle database represents a LOT of overhead. For instance, an empty Oracle database takes ten times the disk space of an empty postgresql database. Worse, every new database is a new administration burden.
We wanted to do a little bit - a very little bit - with web-based Oracle Discoverer. That meant installing Oracle Application Server, and OAS created its very own infrastructure database. Now I've got this "infrastructure" database sitting around, doing next to nothing, soaking up almost as much disk space and memory as a small production database would. It's 9.0.1 - way behind my own databases - and I have to attend to its obsolete 9.0.1 security needs, or the network security scan gripes at me.
And the shame of it is - a use like this doesn't need the things an RDBMS provides. A store of configuration data for an application server doesn't need multi-user access, transactional consistency, etc. etc. - totally unnecessary. A few flat files would do fine.
It's like a trucking company that won't use a hand dolly because, well, they're a trucking company. So, of course, they need diesel pumps and regular oil changes and overhauls for the big rigs they use to get the copy paper down to the copy room, and maneuvering the 18-wheelers between the cubicles may be a little troublesome sometimes.