McKinsey has over 20,000 employees and $10 billion a year in sales. That’s a bit larger than “CIA front company” as you put it.
It’s not surprising that a lot of successful people have worked there. They make it a very attractive place to go work, and if you do well there, anyone will hire you.
With the more recent intelligence community restructuring, officials have also been vexed by what appears to be a lack of a competitive bidding process — McKinsey seemed to seamlessly transition from working with CIA, to NSA, to ODNI via no-bid contracts, these people said, despite lingering skepticism over the firm’s effectiveness.