What's the point in mapping users in SQL Server Data Collection? In SQL Server 2012 R2 Enterprise, whenever I check Management\Data Collection, right-click --> Configure Management Data  Warehouse , I see whatever users-accounts-logins except the one I am logged in 

  

I cannot understand what's the point in "Map Logins and Users" in Management\DataCollectiion of SQL Server?
When you create the management data warehouse, the current login will be added to all three roles, making it an administrator of the database. 

The dialog above lets you add other logins to the roles, to make those people readers, writers or administrators of the database.