[Practicality]

I think this is because they spend most of their lives dealing with unnecessary conflict and isolation since most people don't understand them. Being a genius doesn't remove the need for social acceptance built into human beings.

As such many with a genius IQ pretend not to be in order to be accepted. So their talents are wasted.

However, if everyone was augmented there would be no need to pretend to be "normal" just to be accepted. So much more could then be accomplished.

In fact, I think today's "normal" would be tomorrow's "intellectual disability."

There are many successful geniuses as well. And those are often wildly successful. Again, if everyone was that way it would be acceptable, rather than odd, to care about real achievements.