The people in power circle the wagons around their preferred cliques, because they don't care about the business succeeding nearly as much as their buddies (because there's always the next job.)
Then often the folks are left to do more work with the same pay and the impression that a random draw occurred and they lucked out, nothing more. It really can sour previously hard working folks and have them become that employee that you then think you need to get rid of.
The truth is that most companies are not made of "only A-Players" and that its basically impossible to staff such a company, so you need to limit the damage anyone can do, create systems of checks and balances, reward brilliance and have clear objective levels of work people need to meet to keep their jobs.