I have observed two reasons for this problem:
1) Average people often feel uncomfortable around people who are much smarter than themselves. Because average people are the majority, they get to decide how most things get done, so they suit everything from built environment to rules for their own tastes. This leaves out a lot of others. They also get to do most of the choosing when it comes to college admissions, hiring for jobs, etc. They pick people they like, and they like people who are similar to themselves or a little smarter.
2) Really smart people often find less smart people really fucking frustrating. It is unpleasant to unbearable to be constantly held back and pushed down by idiots, when you could do things better and faster on your own. This inclines a great many genii to say "fuck this shit" and go off on their own. It is much the same as the leaking pipeline problem where women don't want to be around sexists, among other reasons for leaving STEM fields. Nobody wants to stay in a hostile work environment, and most work environments are designed by and for average people which can make them very off-putting to very smart people.
1) Working alone actually works great for many a genius. Unless they are strong extroverts -- and most genii seem to be introverts -- this is often a better choice than teaming up with less-ept coworkers. With that in mind, consider careers that focus on working alone with minimal interaction. In these fields, interpersonal drag will have the least effect.
2) The problem is primarily caused by shear between widely divergent levels of intellect. Therefore, if people cluster in groups on the same level, they will be much less likely to encounter these problems. This is great news for startup businesses, artist collectives, and anything else that can be run by a handful of folks. If you can find a few like-minded people, whatever your level, it is likely to work. However, if you are marketing to an audience on a different level, you will need someone who can comfortably translate between levels; that is, about midway between them.
3) If an organization knows about the intellect-exclusion problem, it can take steps to buffer that. Let people sort themselves into compatible groups, whether these are homogenous or heterogenous. Let them also have choices about where and how to work, so they can customize the environment and activities to their needs and interests. It's not good for people to work against their nature or do things that make them uncomfortable all the time. They need a comfortable work environment, compatible coworkers, and tasks that are challenging rather than boring or overwhelming. A large organization can capitalize on diversity by having groups at different levels of skill and intelligence, in which the ordinary problems are handled by average workers and the bleeding-edge problems are handled by genii. There is some difficulty in communicating across the layers, but this can be done because IQ is a spectrum not a set of boxes. There will always be some folks middling between clusters who can communicate with both; use them wisely, pay for their skill development in communications, and listen to them. Big organizations like software companies or activist charities are sometimes quite good at this approach.