How to setup voting on user profiles?
if you end up getting stuck, you could create a Rule that populates a node when a user is created, and essentially create a node-based profile that the user can edit, then use Rate. Look at Node Limit to limit the profile count to 1 node per user, and set permissions on the content type to restrict the user being able to only edit (and not delete) their own content.

Rules:


  The Rules module allows site administrators to define conditionally
  executed actions based on occurring events (known as reactive or ECA
  rules). It's a replacement with more features for the trigger module
  in core and the successor of the Drupal 5 workflow-ng module.


Rate:


  This module provides flexible voting widgets for nodes and comments.


Node Limit:


  The Node Limit module allows administrators to restrict the number of
  nodes of a specific type that roles or users may create. For example,
  if a site has an "Advertiser" role that can create "advertisement"
  nodes, then the node limit administrator can restrict all users in
  that role to a specific number of nodes. He may also restrict users on
  a per-user basis.