The other day, the only space faring races were (I kid you not) the Thoraxians, Peltians and the Burlust. The Acutians were my 'whipping boy' race, I started out with blowing up their flagships in the first mission and things got worse from there. I would routinely augment my available funds by selling Acutian pilots to the black market slavers (they're robots so who cares, right?) Not only did I get a butt load of credits, but my influence with the three spacefaring races skyrocketed.
So, sometimes it's a win win, sometimes it's a win-lose. I would say 'never' is inaccurate.