It's important to note that Steele isn't supposed to be 'Action Jesus' of the universe, unless the player chooses to go paragon or renegade there's never really a reason to get involved in anything.
Why would someone like Steele go after the leader of a pirate army or sex slave ring? Unless...
Nah, you can meet the new elder 'Elder Maxson' in Fallout 3, who was a kid called Arthur, he had a crush on Sarah Lyons, unfortunately this is just the Brotherhood going down a bad path, if anything the outcast are the most logical reason