It's a good question hoot and one that I don't really have a good answer for. One thought is that part of it stems from the idea that they have been generally in decent socioeconomic positions and have more to lose than others in recent centuries (see Germany 1930s). Another could be the longevity of the religion and its historical struggles with so many ethnic and religious groups (e.g., Babylonians, Greeks/Macedonians, Romans, Christians, Muslims, Ottomans, etc.) has made Jews less interested in war and physical conflict.
Either way, the lack of standing up for themselves when things turn violent or go beyond verbal means, is troubling.
