A lot of parents are misguided about the idea that their children may make the national team or get a college scholarship if they take them out of school to focus on gymnastics.
But even if a child never makes it to these goals there is still great value in taking their gymnastics to this level. This type of serious training will teach them dedication, Committment, goal setting, focus, determination, courage, persistence, excellence and passion. And it will usually teach those lessons far more effectively than a school will because the lessons are taught doing something they love and are truly passionate about.
What they do in the gym may not lead to the national team but it will lead to them being highly employable and successful in the areas they choose to pursue in adulthood.
Many kids do better in home schooling than they do in traditional schooling too. Especially if they are visual learners (which 75% of kids are) and if they are self motivated (which the vast majority of gymnasts who reach this level are). They can often get their school work done in a fraction of the time when they are dealing with the day to day drama of disrupted classes, fire drills, assemblies, roll marking and so on. And there isn't the need for hours and hours of homework, which is often just busywork, or expected as a form of teaching discipline (gymnasts get that discipline in the gym).
I would feel that while some parents would be misguided and think their child can go all the way in gymnastics, most would have multiple reasons for choosing this life style.