There was once, a long time ago, a sport called American baseball. We named the teams with derogatory names which inflamed the Native American Indians, and eventually the names went away. Just because we were insensitive to a race and a culture and then blamed it on our ignorance, does not mean we should continue just because it was acceptable culture at the time, or part of the games DNA. Not good enough sir.
When I hear the word "slave" I hear another derogatory word in it's place (I won't mention the word here).
When I hear the word "stolen" I hear another word, "thief". No matter the context or excuse.
So, we acknowledge one race and delete the derogatory words from our vocabulary and games, but we exclude all others?
There is a wider audience here than you realize.
Political correctness changes like the wind, for example in the 80's it was deemed PC to use the word coloured instead of black and now it's the opposite.
In the bible, slaves are not only common, but it actually tells you how they should and should not be treated, as if the question whether slavery is right or wrong is not even considered.
There is no need for such discussions in a game like this though as the main point of the game is 'choice' and 'freedom'. That's the choice and freedom to play the game the way you choose, as in evil over good or vise versa. Things like criminality are all part of the game, if you remove them then you have no game. If you don't like that then don't play, and I don't mean that as an insult. I would not let my six year old son play games like GTA for the same reason.
Comparing it too American baseball is silly as that is not a role-play game. I don't know the history of American baseball names so I won't comment, but I can imagine, but it's a very different thing to the portrayal of human behavior. Everything in Elite is 'real' there IS slavery in the world, hiding it won't change that.
EDIT: One thing should be very clear, the criminal representation in Elite has nothing to do with race.