The ONLY redeeming feature of such policy is that the people who dutifully report each and every cent of income are hit harder than the people who take the "I'll report what they know about" approach and most of the people who support these policies tend to be in the former group and that's pretty paltry as far as silver linings go.
(1) Minor transgressions shouldn't be ruinous for anyone including the poor, that's part of the point of scaled penalties.
(2) Ideally, the point would be your quality of life when you are not being punished for crimes, not the ability to be effectively immune to meaningful punishment for crimes that would ruin others.
So then why do scaled penalties only ever seem to be scaled up with income rather then down with lack of?
The two are equivalent, and many scaled fine systems have lower fines for equivalent severity offenses at low income levels than are common in the systems of fixed fines used in the US.
A lot of people get fixated on, e.g., Norway's very high, even at low income levels, traffic fines compared to the US, but that's a product of Norway being a high outlier in how severe traffic violations are considered (and, also, the US being a low outlier.)
Legislators seem happy to create fines that are meaningful if not excessive to everyone with a household income short of two well paid white collar professionals (who themselves are a small minority).
The people who are on top of the current system are the last people who want to unbalance, damage it or otherwise rock the boat.
Why does the government get the privilege of also being financially ruinous to those who are otherwise financially stable?
The whole point of money is to be able to make problems go away with minimal effort. Government scrutiny is just one type of problem. It's a leaking water heater with a badge and a gun.