No, but we often do need them to deal with bears..... plus, the species they met might not be as helplessly primitive as we are..... no garuntee that the bad guys wouldn't be as advanced as they were, or perhaps more so.
IN which case that said species would be an enlightened and peaceful one. There is one logical argument which is consistently being ignored in modern sci-fi flicks (for obvious reason that no one wants to see peaceful aliens) - that interstellar civilizations are necessarily peaceful ones. Why? Well, if we observe the progress of our race, we can see that as our technology advances, more and more power is placed in the hands of an individual. A few hundred years ago, the most direct power a single human being could have was contained in simple leverage principles and sharpened bits of metal.
Today a single human being can easily cause widespread destruction using the latest weapons and explosives.
By extrapolation we come to the conclusion that the level of technological development necessary for faster than light travel and gravity manipulation is so high compared to our, the amount of personal power a single being gets is immense. I am talking about melting half a planet with the push of a button. So in order for such a species to even have a chance of surviving, individual members must excersize utmost discipline of mind and posess a deeply ingrained sense of personal responsibility and peacefulness on the level which would put Dalai Lama to shame.
Such people would have no notion of using violence to achieve whatever they need. This is what I meant by anthropomorfication - humans are used to solve their problems by shooting stuff. The basic premise of the movie is hard to believe because you feel like you're watching a five year old kid molesting a terminator. Only the terminator is so stupid it doesn't even know its being molested.
In our history, issues like racism, slavery and inhumane treatment of our fellow humans were always perpetrated by the powerful. Never by the (technologically) inferior cultures. So it feels odd that a starfaring race would be so boxed-in by a bunch of recently-hairless apes.
One more point - the main protagonist and his Kafkian metamorphosis. I understand why it was put in - so that he, a blatant racist, can see the other side, as it were, by literally wearing their boots. However, I think this weakens the whole change of attitude that he goes through (although his base selfishness and cowardice are well portrayed throughout the movie all the way to the end when he finally decides to do something for someone else for a change). I think the realization of his own wrongdoings would have a much more profound impact if he remained human altogether and managed to break through the racism and inhumanity without the external aid of a horrific mutation and subsequent inhumane treatment by his former colleagues.
The movie does one thing well though - it portrays basic xenophobia ingrained in the human culture well. I believe that faced with another alien race, humans would most likely react with fear and prejudice, resulting in hatred. It is extremely unlikely that we would be able to exert such dominance over the newcomers as shown in the movie, a fact which is half covered by the remark that most of those aliens are really that stupid - in fact not representative of the power of the alien race at all. Come on, the guys couldn't even leave their own ship, humans had to cut their way in!
Guns are my biggest issue here. Its unlikely a starfaring race would have any need for them. In fact, said races would probably have no notion of violence at all... with technology on the level closing in on omnipotence, what need do you have for projectile weapons?