Primaries are a process of selection, not one of election. There are plenty of other situations in which political parties recognise the need to introduce particular expertise into their processes such as in drafting policy or developing campaign materials.  Superdelegates act as a balancing mechanism in the event of an emergency or a tie. Other than that the system simply ensures that the winning candidate has a clear majority and to provide the leadership with the party a legitimate reason to attend and show their support to those watching at home.  Rather than providing an unwatchable parade of faces and names that the electorate has never heard of the superdelegate system means that senior party officials have the opportunity to say that they have actively and publically voted for the successful candidate.