There's a few legal benefits with the 5k. If your max punishment is 5k, then they can't entirely rackateer you into settling like the US. In the US they do stuff like pay 5 grant or we'll sue you for hundreds of thousands. That prevents alot of cases from going to trail, because someone can probably scrape up a few grand over time, but 50 grand, 100 grand, they would have serious reprecussions.
So with a 5k cap, alot of it could go to trial, because the max punishment would be a 5000 dollar fine. Meaning the legal costs for the CRIA/RIAA could kill any benefit from recieving the fine (if the gov't even bothered to give them the fine).
The legal costs in the US must be downright low, because most of the stuff is settled on an internet website without going to court.