This is an excellent question.
First, we need to start off by pointing out that the movie, despite is modern and beautiful facade, is a dystopia. What seems great on the outside, on account of genetic engineering, is a society that is plagued with all sorts of hardships.
Second, the theme of brutality comes to the fore, because such an enlightened society is incredibly intolerant. They judge people simply by their genetics. People in this society fail to realize that people are far more than their genetic composition. The tag-line in IMDB says it all:
"A genetically inferior man assumes the identity of a superior one in order to pursue his lifelong dream of space travel."
Third, in light of the above point, the essence of what makes man is taken away. Things like, will, character, determination, perseverance, creativity, and many other important qualities are not taken into account. The irony of the movie is that the protagonist, Vincent (the genetically inferior man) is superior to all others.
To judge a man by this is brutal. It is to kill the human spirit.