This is true of almost any club (the Free Masons, your local BPOE, Boy Scouts, etc.). You join, you get to know people, those people help you with your interests, and in return you help them with their interests. It isn't particularly difficult to see why this success might backfire and reduce/limit actual innovation, because it creates a powerful echo chamber – in part by design, to achieve specific goals, and in part by accident, because the people accepted by the club tend to meet predefined expectations.
The problem is, as I see it, that escaping that kind of feedback loop is very difficult, once an organization is in it, because the momentum making the loop bigger is difficult to redirect into an energy to make the loop different. Harvard could announce that it will no longer accept children from powerful/wealthy families, Davos could release a statement that this year it will be hosted in conjunction with the Communist International, and YC could relocate to Uganda for a season – but that's not what these organizations do, so after a point, they aren't able to innovate outside of very specific boundaries.
The answer to that, of course, is create new organizations with different boundaries/priorities, but Christ, that reeks of effort.