Marketing, packaging, competition and cost drives the way Chipotle, Subway and Microsoft put together their products. The user is only one factor in the equation. When we develop apps, the same is often true.

Applying this to SQL Server, how many people use it as a only a relational database engine? Or use less than 20% of the features? I would say most.

However, as a consultant who architects solutions for clients that include a relational DB, a data warehouse, ETL, cubes, data mining, and reporting, then I'm happy to have all the solutions I need under one product line. This makes it much easier and cheaper than bringing together a number of different apps.