They are many levels of problems in Germany linked to kava.
The first is the protection of the industry and to avoid prosecutions. Hence, instead of condemning people that have sold poisonous kava extracts or synthetic kava in Germany, that should normally be in jail, the plant has been condemned instead. From the diesel scandal (VW) to the Lipobay (anti-cholesterin from Bayer), and in contrast to the US, almost nothing has been done for the victims in Europe. The same for the victims of misused and altered kava. Hence, using kava as scapegoat allows to save both face and money.
The second point, brought correctly by TheBastian, is the battle inside German's official institutes between the scientists and the alternative medicines. Particularly, inside the BaFrM ( in charge of establishing the safety of medical drugs) special departments have been created to evaluate homeopathy and anthroposophical drugs (the anthroposophs believe that your illness is due to your behavior in a previous life) besides any scientific facts. Whatever one may think about those pseudo-medicines, the drugs produced for the homeopathy users and anthroposoph believers bring a huge amount of money to the country and therefore political power. Hence, there is in Germany a delicate status quo between the scientific medicine and the two above cited alternative medicines : there is almost no place for new comers like kava, that is neither interesting for the big pharmaceutical companies nor for the alternative medicines for which the plant is not linked to some magical virtues. In other words, kava suffers in Germany from the fact that it has first entered the market thirty years ago as a health product. Politically, one can easily understand that it will be difficult to downgrade it to a simple food supplement. Hence, indeed, scheduling it like legalized cannabis in a near future may be a solution.
