Well, if the domain expert wrote the first pass at it, think of the cycles of writing specifications, design, programming, and only then finding out the specs were wrong, got skipped.
That's a huge time savings, and as a bonus you have working code to refactor or use as a specification.
Microsoft Access is an amazing database, it manages related tables automatically, and can scale up to working with ODBC and SQL database back ends easily.
Until it needs to maintained and scaled.
My first job out of college was to rewrite a data entry system for a state government used to enter crime statistics. They used Microsoft Access.