"If the audience is supposed to accept that genetic determinism is true in Gattaca, then no amount of Vincent's hard work should make Vincent a hero. He's just a fraud. If the audience is not supposed to believe that in the world of Gattaca genetic determinism is true (that is, it's false), then it should be interpreted as a story of discrimination, and a story of the underdog's heroic hard work overcoming the negative effects of a corrupt, wrong, erroneously-discriminating society."
from http://www.ln.edu.hk/philoso/staff/sesardic/Gattaca.pdf