Do you think it has to do with generating income? Like if someone is homeless the odds of getting them to pay a fine is next to nothing. But snag a guy walking out of a bar pissing on the wall you're going to get some money out of it.
If you have a home / money, a fine or brief jail time are punishment. If you don't have home / money, you won't pay a fine, your time and lack of freedom won't solve an addiction brought on by being desolate. So, a month later, a cop has wasted hours, a judge has wasted hours, and the "criminal" still can't pay the fine, is still addicted, and will waste that same time again.
tldr; A fine of $50 for someone who doesn't have money to eat is in ways as inconceivable as a $1bln fine to someone in the middle class.
that's almost certainly not true. a fine is primarily a deterrent, and failing that, is punitive. it's not corrective (or restorative), because it doesn't "correct" anything.
an example of corrective action is a burglar being required to return/replace stolen items.