When you bill by the hour, the more hours you work, the more you bill, the more you make. 

No matter how imperceptible, the incentive is to make work take longer, at a minimum, not find ways to make the work go faster.

You might:
 

• Not learn keyboard shortcuts – just mouse-around

• Not use an online calendar – email back and forth 6 times with the client to find a time

• Not streamline processes – "it's clunky and inefficient, but it works"

• Not invest in powerful software that provides valuable answers in seconds

Anything, to ensure the job doesn’t go faster.