When a major record label signs a contract with a band, the label assumes considerable financial risk  It pays for videos, album art, management, and promotions  Hence, the band does not need to assume nearly as much risk as it would if it produced its own records independently
For this reason, it is only fair for a major label to take a large portion of the profits from the record sales of any band signed with it
It is a general principle from which the argument's conclusion follows as a specific instance.