Rogue definitely sounds cooler ;). Unless you type it wrong and give it a whole new meaning with "Rouge Squadron."

I see what you mean about the popularity of background characters. I think part of it is the tendency of fan geeks to obsess over the smallest detail, even the third stormtrooper on the left. And part of it is showing your street credibility by being so knowledgeable about SW, you know who Gonk, Bossk, and Bultar Swan are. You may be right about the "blank slate" theory as well.