Kind of a no brainer for some people who wouldn't mind being famous.
This one last step from being really good, to being insanely good at something often means your become a public figure, and personally that scares me a lot.
You sing? If you want to really be successful, people will know you.
You do sports? Same.
Politics? Same.
Even just holding a high power position in larger companies means that articles could be written about you.
The thought of losing privacy and even worse, forever be hunted by paparazzi just kills me. I would never want that and no matter how good I would be at anything, I wouldn't go pro just because of that.
I'd rather be an anonymous normie than a super rich mega star who can't walk out of the door anymore without someone recognizing him.