More serious and higher ranked folks have also spoken. Like Appellate Judge (and etc.) Hoeren. http://www.oii.ox.ac.uk/resources/feedback/OIIFB_GPL3_20040903.pdf
I am not a lawyer and I cannot comment on every objection. But there are arguments that obviously seeems flawed and I am very suspicious for the others.
It is reproached that a German court apply German law (?!?). A Germanian bring a lawsuit in Germany for infrigment of a license he have choosen. It is obvious that German laws will apply. The fact that this license were written in the U.S. and the history of the license is not really relevant in this case.
It is reproached that the term "license" does not exists in the E.U. But if a term in a contract is not exactly the perfect term or is even wrong that does not mean that the contract as a whole is null. Especially that the definition of a "license" is not really important to understand the GPL
The jugment speak of the possibility that there were no contract between the parties and yes in this case there is copyright enfrigment. Copyright law requires *explicit* permission to distribute copyrighted materials; if you do not have the permission you have no right. It would violate equity if you give the permission to distribute the software but use invalide terms and then sue the people which have respected what they believe they was right. But if you say that people may not redistribute (as the GPL which say that you may not redistribute if you do not provide source, etc...) even in invalide terms; it would not amount to give an explicit permission to distribute (which is required).
As last I do not know exactly "German law" but in Belgium (which I think is similar) you do not need to use "valid legal terms" for a contract to be valid. The court usually interpret contract as "what a normally educated people will understand". Exept a few technicalities (which are of minor importance) the meaning of the GPL is perfectly understandable by everybody. It seems to invalidate many of the objections made by these people.
Olive