Ali,

In Judaism, most Jews were once closest in terms of religious paradigm to what today we might call "Modern Orthodox." But today, Modern Orthodoxy is a minority viewpoint in the Jewish world. Most Jews are liberal (Reform, Conservative, Reconstructionist) or secular. The ultra-Orthodox world is increasingly the dominant form of the traditional Jewish world, and of course, even some of the Modern Orthodox have moved into a far-right militant Zionist understanding of Judaism.

One reason is that it is more difficult to simultaneously maintain a belief in both religion and the science of the times. It is easier, even if strange, to reject science in favor of a literal understanding of Creationism. Once you could embrace scientific method without seriously compromising faith. Today, it is much harder. Something has to give, and when it is scientific method, and when it is engagement with the secular world in a constructive way, this pits the respective faith against the world. This leads to radicalism of thought, and pressure upon others to do the same. Fundamentalists are then able to frame traditional adherents as illegitimate compromisers, even though the traditionalists are the ones often coming from an ancient paradigm of allowing for various viewpoints and expressions (including, of course, lenient viewpoints), as well as engagement with the larger world.