A problem working with young people is that they often do not take the long view of athletic (academic, financial, etc...) development. They want it NOW. The sooner the better. While there is nothing to be gained by unnecessarily delaying gratification in and of itself, if the goal is long term development and retention of skills, technique, speed, strength, knowledge, etc., then "go hard or go home" methodologies and mindsets are often counterproductive.
Many years ago, I was coaching a 9 year old boy who was a very competitive swimmer. Let's call him Mikey. Mikey was successful and won many of his freestyle races. In practice, he would do flip turns when coaxed, but in competition he would always do open turns. Why? Because Mikey was faster with open turns, of course! He was very reluctant to switch from open turns because he had had success ("If it ain't broke,...") and only after I had convinced his dad that the change was needed was he even open to direction. I worked with Mikey during private lessons and regular practices for weeks. Oodles of positive reinforcement and several meets (and some tears of frustration) later, Mikey was hitting personal best times again with flip turns and room for greater and greater future gains.
Interestingly, at around the same time period, I had a similar experience convincing my father to do flip turns. He believed that because his goal was ultimately to become a faster open water swimmer (lakes, ocean), flip turns were unnecessary. Simple logic (more time turning in the pool equals less time swimming vs. faster turns equal more actual swimming) made the argument a short one.
Every competitive swimmer and coach knows that flip turns (done well) are faster than open turns. Much MUCH faster. Can you break 30 seconds in the 50 yard freestyle with an open turn? Yes, but it's harder. Can you become an All-American freestyle swimmer with open turns? Maybe 60 years ago, but almost no one could today.
It sometimes requires sacrifice to make the changes needed for long term growth. In Mikey's case, he had to give up some potential victories, points for the team, and PRs in order to master flip turns. In my father's case, he had to sacrifice some training time and effort on turns that could have been spent grinding out more training miles.
For many young people (and often their parents) it is difficult to see the benefit of making short term sacrifices that lead to long term (and greater) development vs. choosing short term gains that come at the expense of long term development. Technical change can be difficult, especially if you've already been training for years. But, an athlete will relatively quickly reach the limit of their physical potential using less than optimal technique. As athletes (and their goals) mature, technical demands may change and this needs to be accounted for. You cannot cram mastery.