which is the an outcome that was produced by the societal bias towards imperfect people.
For example, instead of denying the role to him purely based on genetics tests, they could measure the actual performance against a standard (a standard which you'd need to perform at to do the job).
Then, if he is predisposed to heart failure, there could be provisions made to ensure it doesn't interrupt the mission or endanger people on board. Even perfectly healthy people could get a heart attack due to something unpredictable, so having the facility and knowledge to handle such a situation is good regardless.
Instead, the society is choosing to eliminate heart failure (or failure modes) - and i think they're blinded by the idea that they must've succeeded by using genetics.