It's the belief that management is science.
Management has very little to do with science (although there are tons of studies of actions that do and don't work from a management perspective) and should be mostly about dealing with individual personal issues, the things that make employees non-interchangeable, the things that keep employees motivated.
Unfortunately, it looks like very few organizations are able to apply modern management strategies that help workers stay happy and motivated. Workers are often regarded as interchangeable Lego bricks. Taylor inheritance? Corrupted business schools?
The three essentials for motivation from a managerial perspective when dealing with non-repetitive work are autonomy, flow-mastery and purpose.
Autonomy is essential for happiness. You need to feel like you're making the decisions that affect you directly. This will probably be the hardest one for traditionally-schooled managers to absorb. Employees come in whenever it works for them, work at home, meetings are not mandatory by default and there are no time clocks. The only thing that matters is results. Superfluous to say is that autonomy builds on trust and purpose.
Flow is the daily satisfaction you get from doing something that's not too easy but not too hard. Ideally you get flow every day, and it's what carries you through the difficulties of achieving mastery.
To achieve flow, you need:
Continuous flow leads to mastery over time.
- Clear goals
- Immediate feedback
- A challenge that is not too easy nor too difficult
- Something that engages you
- Enough structure
Examples: TDD, iteration ending with functionality demo
Purpose is the feeling that you are working towards a higher goal. The idea that there's a reason (mainly non-profitable) why we do what we do (Maslow's self-actualization).
You really need all of them in order to feel happy & motivated. For example, you could be working in an environment where you feel autonomous but you get no sense of flow at all (not enough structure, no feedback in time).