There's no equivalent in class action suits in germany. And then, the company claiming the copyright violation is a swiss company, so to counter-sue and receive a compensation for your costs and fees, you'd have to sue them in switzerland under swiss law. The claimed amount is low enough that it's way less costly to just pay up and leave it at that.

For the general good it would be better if everybody countersued. However, what I can see coming in this case that the matter may proceed to become a criminal case against "The Archive" which then would be a different story. There's still hope.