It's like this, I'm British. While I don't live in G.B. I still think of myself as being British. The thing is The Republic is American and the sith have British sounding voices. The Sith are the bad guys in this game. Even though I play them.
Should I therefore be affronted that the makers of this game have used British sounding voices for the sith?
I think the Republic should be insulted that you compared them to Americans.