Graeber has been pushing this for some time now - it is an interesting observation. In this particular article he does not even try to explain why this happens

Graeber has been pushing this for some time now - it is an interesting observation. In this particular article he does not even try to explain why this happens - but in other places he made silly theories about capitalist employers doing that on purpose to keep people from revolting - while omitting the simplest explanation - that it is the result of complexity of our organizations. People don't understand their jobs. Sometimes it means they do something useful but they don't understand why it is needed, other times they really do something useless - but nobody really knows which is which or what part of a job is useful. Then there are company power plays which are counterproductive to the whole - but they are meaningful for the people who commandeer them. And the biggest problem is that there is a positive feedback in that - after a few failures to rationalize the organizations people give up. The harder the organizations are to be understood the less people work on making them more rational.