So many theories, when the truth is out there for all to see...
British accents are sexier than American accents.
End of story.
I must agree. My greatest sorrow when running the class quest line on Voss was that I could not loot the Sith guy's wonderful Scottish accent after killing him. Oh, and that one Imperial officer on Hoth who's working with the Republic to take down the White Maw Pirates. DAMN, I want that accent.