Fines are meant to be, on the one hand, a deterrent, but on the other hand, a less severe consequence than incarceration.

By that logic, fines can’t be uniform regardless of income. Because if the uniform amount is set too high, it becomes too severe for low-income individuals. If set too low, it ceases to be a deterrent for high-income individuals.

The only way to achieve the objectives of the law is to use a sliding scale.