It's particularly unfortunate because it would have been so easy to fix. The risk to others is unnecessary to anything the movie is saying. That it wasn't fixed says to me that either the writers couldn't be bothered to think things through, or they believe that personal ambition is worth any price, even the lives of people who don't consent. Neither alternative is very attractive.
Interesting viewpoint! It seems to me that the genetic testing was nothing more than a convenient proxy for measuring actual performance. The proof is in the pudding, as they say, and by actually performing, Vincent proved that the proxy was (in many ways) flawed.
> either the writers couldn't be bothered to think things through, or they believe that personal ambition is worth any price
The whole story is about emotion vs. reason, about whether or not the human spirit can be neatly quantified, categorized and filed away, and about the complex trade-offs involved. I think it's more likely that the writers were aware of this aspect of the plot, and gave us that much more food for thought...
The tradeoffs are never discussed, and the protagonist never so much as acknowledges that his pursuit of his dreams might cause harm to others.
The proof of the pudding is in the eating, and this pudding isn't eaten until Vincent's mission returns safely. When the movie ends, he has not come close to proving his performance for that.
Teams generally work better with a mix of different people, rather than uniformity. I'd be willing to bet that if the scenario was real, the mix would work better.
There are a lot of people out there who want to become astronauts and are rejected because they're not healthy enough. The reaction is almost always "that sucks for you, maybe you could go into something related to space so you're at least still doing something related to your dream," not "NASA sucks, they're building weaker teams by excluding people they think aren't healthy enough for space travel."
The swimming story is the inner story for the bigger outer story, but that's the heart of it. The bitter cripple who lends his blood points a very harsh light at rational disillusionment. Any system for genetic selection will impose a model of what ought and what ought not be; we should be wary of what it selects for, because it might not be what matters most.