Why Graph?
The bulk of my experience with application development has been building workflow-related rich client and web applications on NoSQL databases, typically IBM Domino. The challenge in the Notes Client was to provide dashboard-style displays and a good way to display documents for action by the current individual. Private views can be used, but impact database performance. So, typically, the approach is to display views that present a scrollable table of data. Domino's document-level reader security is then used to ensure only the appropriate data is visible. If data is archived appropriately, performance of the database is good enough for many reasonably-sized applications. (Of course, archiving is often omitted from scope of the first phase for the rapidly-developed application, and becomes a case of "out of sight, out of mind".) But with the increasing prevalence of web applications replacing Notes Client applications, the ability to display "my documents" and use structured searches to display a targeted subset of documents was much easier.