Double entry bookkeeping is a view that was confused for a model centuries ago, and has persisted ever since.
There have been attempts to correct this, such as the "Resources, Events, Agents" (REA) model[1], which according to the Wikipedia article "is a standard approach in teaching accounting information systems." But it doesn't really seem to have had a substantial impact on the practice of accounting.
The bottom line from a modern system design perspective, is that double-entry accounting makes much more sense if you treat it as a view of some more fundamental underlying model. REA provides one example of such a model.