It takes considerable knowledge and courage to first sift through the history and find the facts and then view them objectively through the prism of Islamic teachings (especially Quran puritanically) and then finally speak the truth publicly without the fear of rejection, hate and other threats.
We have been fed wrong things wrapped under the foil of religion for ages, and we unfortunately fall for the shallow appearances instead of breaking things into the fundamentals taught to us by our religion. If a Muslim is oppressing others regardless of how pious and Islamic he may appear, he is still wrong. That's what Jews, Christians and all other religion-followers need to do. Depriving the romans of their sons and pitching them against their own people was wrong. Whoever did it, still it was against the teachings of the Quran.
Everyone has some idols in his/her mind those are difficult to break and when someone with wider and deeper knowledge comes and tells us that we have been wrong all this time, most of us often find it very very difficult to accept. We have some national heroes, however they also committed key mistakes, mostly unconsciously or due to their limited understanding, that amplified into blunders over the time and we are in the mess because of those mistakes. That is why it is always good to go back to the drawing board, consult the original reference (Alhamdulillah we have them i.e. the holy Quran, the authentic Hadeeth and the holy Quran (again: to filter out the hadeeth that conflict with the core of the holy Quran)).