What I'm reading from your comment is that you have a strong, implicit association between "giftedness" and "notability" - perhaps the latter taking the form of socially recognizable achievement.

Speaking as someone who was in a gifted program in my youth (and who knew others in more advanced programs), I would like to caution against this perspective. My achievements are not notable, and I would not use that as a heuristic for determining whether or not a particular program/standard is successful or useful. Yet I found my experience to be very positive. Despite the fact that not all programs are created equal, I would generally recommend a suitable one to any parent with a gifted child.

I understand MENSA is a bit loaded since it can come across as pretentious, so let me reframe the example for you. Take a look at past winners of the Putnam exam. Most of them are not nearly as notable as cperciva[1], but they're all demonstrably gifted.

Giftedness is not about being entrepreneurial or about how you apply your intelligence in a notable way. Programs designed for gifted people are not trying to create a class of people who are more impressive. In general, they try to foster natural talent in a way that cannot typically be accommodated in the modal classroom setting.

________________

1. For those unaware I'm referring to Colin Percival, an HN user who designed scrypt and developed Tarsnap. He won the Putnam.