It's a few things.
1. Sales people see the exact dollar amount they are making for the company. This is different than almost any other role. Most people can't quantify how much value they generate. A lot of people here are arguing that the reason is that there is a direct quantification, but that's not it. The reason is that there is a direct quantification AND they know exactly what it is.
2. These are people that convince others of things for a living. The skills that allow them to be good at their job also allow them to negotiate for extremely favorable compensation mechanisms.
3. At this point, it's how their industry works. If you try something else, you won't be able to hire sales people. They are very competitive, and not idealistic like engineers. You're not going to convince them to take a flat comp structure that is the same as every other employee's.
2. These are people that convince others of things for a living. The skills that allow them to be good at their job also allow them to negotiate for extremely favorable compensation mechanisms.
3. At this point, it's how their industry works. If you try something else, you won't be able to hire sales people. They are very competitive, and not idealistic like engineers. You're not going to convince them to take a flat comp structure that is the same as every other employee's.