Frankly, that's a pissweak argument against significantly harsher penalties for poor people vs wealthy people. The transgression committed is the same, so the punitive impact should be the same. Instead we get a much reduced penalty for wealthy folks (both relative and absolute) - and the difference has zero to do with the nature of the transgression.

This particular penalty is 25% of the full amount if you happen to be decently monied at the point of being fined - it's almost explicitly a 'poor tax'. Almost.