[wakawaka28]

People in general would rather have less responsibility if there is no value added by taking more. This is extra important when the person is highly qualified, because in theory they could do their own thing. So you have to pay more than that.

There aren't many people for whom status alone is enough. Why should anyone take on more problems to end up with less money than if they had assumed less problems?

There is another problem with not paying people. It encourages corruption. When people feel they aren't paid fairly, they will do all kinds of awful things.