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?
Well....except that our dear leader over here in the colonies doesn't think much of you Brit's over there.....you know since clearly that slavery stuff was all your fault!
British accents are cool and the Empire is waaaay cooler than the stuffy goody-too-shoes Republic with their holier than though attitudes and rules!
meh....stay British my friend!