In athletics, genetics is often used as a reason for success and failure. It is a term that is used primarily as physical modifier; he who has the body and athletic ability to play his sport has great genetics. However, sports is filled with many people who are insanely successful despite not having the traditional physical attributes associated with his sport.
Often times players' bodies will fail them with multiple injuries. He can be a tall, strong and fast athlete but his body just cannot withstand the punishment of training, practice and games. He may look like he has great genetics but alas, he does not.
Some people's genetics are more mental than physical. There are countless stories of undersized or slow athletes who become great players/athletes. The general comment will be, "He certainly wasn't born with great genetics but..." However his genetics allowed him to: withstand criticism, mentally prepare and know every part of his game, know and anticipate the opponents game or simply have the mental strength/intelligence to find a way to win. Sometimes it's about willing to do what the other guy's aren't. Many times, one starts at a different point then another person; do you have the resolve, patience and desire (genetics) to make up this ground? Or is this going to be used as an excuse?
If someone "could've gone pro but the coach hated me" then he has shitty genetics because he is too stupid to do what is necessary to play the game. Thus his mental genetics/will to succeed is weak. And let's be honest, if a coach HATED Michael Jordan he'd still play him.
Simply put, if you are successful you have good genetics. Those genetics may look different or be hidden but rest assured, they are there.
So what does this tell us? If you aren't successful, you can now blame your genetics, no matter your situation. Some people simply have "it" or learn to develop "it". It's always been this way and always will be this way. Nothing is fair; one of the most important lessons I've ever learned in sports. Just the same, what isn't fair to your opponent is how you can react to your situation and how you can an edge over others.