Isn’t that called “cronyism” (or “old boys club”) rather than “conspiracy”?
True, although the term cronyism and old boys club focus on the exclusivity of those "elite" circles, rather than the impact of their decisions, which looks a lot like conspiracy from outside.
Some people end up coming up with conspiracy theories based on their outsider observations.
But the older I get, and the more understanding I have over how large organizations are ran, the more I realize that conspiracies actually do happen, but in much more subtle ways.
What actually happens is that over a long periods of time, people collaborate with and promote those who think like them, with similar biases and incentives. Then when a major decision needs to be made, everyone at the table think the same way and agree on the same solution. This works even across organizations, as people's career are made through networks and relationships transcending organizational boundaries.
It is difficult to get a group of people to understand something when all their salaries depends upon them not understanding it.