Most of Scandinavia has no financial privacy. What people earn and how much tax they pay are published online. This would make penalties based on income much easier. The US values financial privacy much more. It's also a very different society. It's easy to imagine precisely what would happen if peoples incomes in the US were published.
Everyone in the US who makes more than 10k (which I assume would be the minimum bracket for a fine) has to file income tax, and it would take a single bill to make this info available for the purposes of assessing fines; it doesn’t have to be public. And sure, some people cheat on taxes, but some do in Scandinavia as well.
The US values financial privacy more, because it's a way to perpetuate wealth inequality.