I cannot argue, since you know the situation in german universities much better than I do. But why then the authoritites prohibited the Arab/Muslim organization Hizb ut-Tahrir? It seems to me they had solid reasons doing so. If some (not all, of course) of the Islamic students' organizations manage to abuse freedom of speech and promote hatred toward Jews even on the Israeli territory, it seems to me that outside Israel they feel even more free doing so. By all means, I do not remember where did I read this, but there was an article stating that the lowest level of popular anti-Semitism, and the less tolerant policy of the government toward promotion of hatred to the Jews was in Germany.
Authorities prohibetd Hizb ut-Tahrrir, because its an organisation against our constitution. (About a dozen members in Germany.)
Some German Neo-Nazi-student organisations are still 'legal', since their case isn't decided yet at the Federal Constitutional Court.
Re. your last: that's fairly true, but actually there are similar laws in most EU states now.
I did not refer to laws: anti-Semitic propaganda is prohibited in all the civilized countries. But I am talking about public sentiment. I used to meet German tourists while being in Turkey and Greece; their friendliness toward Israelis was exclusive, they were always ready to help if we had some problems (mainly, pertaining to navigation; many Turks do not understand English, but know some German, and German tourists always volunteered to help us in communication to the local people; while talking to us they expressed a certain compassion toward our country).