> GPL was written by lawyers for the American system of law and France is not part of the USA.
The important thing is GPL (and other licenses) are contracts. So violations of there terms is a breach of contract and in turn clearly handled by the court responsible for handling breaches of contract.
The interesting part is why it's not (majorly) handled as a breach of contract in the US?
The trick is following or similar sentence (qouted from GPLv3):
> will automatically terminate your rights under this License
Which means of the breach the license contract you lose the license contract and in turn can be sued for copyright violation.
Now the gotcha is not everything you write in a license agreement is necessary valid in exact the same you write it, so now what happens if automatic contract termination is not valid and contracts in such case e.g. exists in-between valid and invalid until conflicts are resolved or similar?
At this point you would still have a contract, one which grants you the right to use given software "just not in given way" and in turn wouldn't it be a case for courts responsible for contract breaches?
Now I know nothing about French Copyright law, but the idea that laws (against auto termination) which would exists to uphold fair competition and prevent abuse might majorly negative affect copyleft licensed open source makes you think.