The way I see, the real utility comes from the fact that domain models such as those in a company's data warehouse are typically very complex, and a great deal of care often goes into mapping out that complexity via relational modelling. It's not just that c bought x and y, but also that c has an age, and a gender, and last bought z 50 days ago, and lives in Denver, and so on.
Having easy access to the probability distributions associated with those relational models gives you a lot of leverage to solve real life problems with.
The way I see, the real utility comes from the fact that domain models such as those in a company's data warehouse are typically very complex, and a great deal of care often goes into mapping out that complexity via relational modelling. It's not just that c bought x and y, but also that c has an age, and a gender, and last bought z 50 days ago, and lives in Denver, and so on.
Having easy access to the probability distributions associated with those relational models gives you a lot of leverage to solve real life problems with.