While using the agile board, there are a few important ways to look at the data:

 - Are there any unassigned tasks?

 - Who is overloaded / underloaded

This ticket is for the last issue.  Sorting by user allows for easier load balancing in sprint planning meetings.  It could potentially also address the first issue as unassigned tasks would be grouped together and therefore easier to find.

This is the view I'm referring to. Not sure of the official name: