When you should fire your most irreplaceable team members

This is great... from a managers point of view. A manager that sees an employee as an easy replaceable part in a machine. A manager that is totally oblivious to an employees workload and the time-cost accompanied with offloading all of one's knowledge into a format that is easy to transfer and teach.

You can write documentation all day long, you can't avoid the fact that someone who's spent 10 years working on a project will have so much intricate knowledge about it that they are close to irreplacable. It takes months for a new recruit to get even close to productive if they haven't experienced that technology before. If you required all your team members to document so much that they could walk out the door and not be missed, you'd never get anything done.