The similar artists aren't based on actual musical similarities. They're based on what people listen to. In other words, Last.fm users who listen to Division of Laura Lee tend to listen to those other artists as well.
Weird list of similar artist, I really can't see much of a connection to any of these except Ikara Colt (well, they have all been on Epitaph at some moment, too, but that's about it). Fugazi or Joy Division or something would be much more accurate in my eyes