Actually, similar plots are not uncommon in games, so they have sparked discussions among players. Many players have expressed disgust towards this kind of plot. In their eyes, it's just like how white people colonized America, slaughtered the natives, and seized their wealth - it's an evil act that should not be promoted.
However, some players argued that this analogy was incorrect. Firstly, the natives of America were also human beings, while aliens were not human beings. They were not the same race, so how could they be compared? According to your logic, pigs are quite smart, and cows have rich emotions. Humans shouldn't slaughter them for meat or use cows for hard labor. What difference does that make from enslaving aliens? Is it just because they look like humans that they should be shown mercy?