If we don't teach our kids to put in the hard work to win, and we allow the easy route of cheating, they will never know the feeling of working hard to achieve something. They will never feel the pride of accomplishing something. The will know what it feels like to win, but they will never know what it feels like to be a winner.
A coach has the ability to make a player feel great about what they have done, whether the team won or lost. Coaches have the ability to give players memories that will stay with them a lifetime, reinforcing hard work and effort, and reducing pain from things a player cannot control. The key is really to decide what the coach wants to focus on, because they have the ability to shape the identity of a kid at crucial stages of development.
Like any area in life, not all behaviours are beneficial or helpful to society and punishments, whether they need to be acted upon or not, need to exist. A player can't walk on to the field and pick up the ball with their hands and throw it in the goal. Doing so will result in a disallowed goal, a free kick, and depending on the age group, a yellow or red card. They are punished for this.
If we continue to praise mastered tasks we'll see stagnation. If we encourage the status quo, we are by default discouraging development. We don't criticise our teens for being potty trained, but we don't praise their toilet-skills either. Praising our teens for their accomplishments is great, but if we want to see further accomplishment we encourage them to keep building on their previously learned skills.
The reality is that the nature vs nurture debate is null. It is impossible to take one side over another and answer all of the arguments against, no matter which side you take. Why? Because in every facet of life there are Messi’s and Ronaldo’s. There are people who are just naturally good, and people who are driven to be the best.