Such is the paradoxical conclusion of Adam Ferziger, author of a new book on American Orthodox Judaism in the past half-century. In an exchange with Alan Brill, he writes:
Among the generation of American Orthodox rabbis that emerged in the early to mid- 20th century, there was a strong feeling that Orthodoxy had to try to appeal to as many Jews as possible. At a time when few congregations existed that could boast of a critical mass of fully observant individuals, it was obvious that Orthodoxy would become obsolete if it only catered to the pious. . . .
Modern Orthodoxy’s Americanized, college-educated graduates were dispatched to communities throughout the country with the goal of creating Orthodox congregations that would offer religious services to the entire Jewish population. With this attitude in mind, some even walked a denominational tightrope by accepting pulpits in synagogues with mixed [male and female] seating. . . .
By contrast, the ḥaredi world was created by survivors and remnants of the leadership of the Lithuanian yeshivas and ḥasidic dynasties who arrived around World War II and directed their efforts toward recreating the institutions and lifestyles that had been destroyed. Fearful of the seductive power of the treyfe medinah (unkosher land)—which to their minds had tainted the already-established Modern Orthodox [community]—they set up enclaves in which they could regain their former strength and vitality. . . Their main objective . . . was to create a community devoted to Torah learning and or/ḥasidic teachings [and] a cadre of rabbis and teachers who could service the needs of recently imperiled communities of the faithful.
More recently, a role reversal has taken place. While non-ḥasidic ḥaredi yeshivas continue to emphasize theoretical talmudic study over practical rabbinics, . . . they . . . have increasingly developed and supported auxiliary programs dedicated to training rabbis (and their wives) so that they can reach out far beyond Orthodox boundaries. Yeshiva University, [the flagship institution of Modern Orthodoxy], meanwhile, focuses most of its energies on in-reach—servicing the highly specific intellectual and ideological needs of its natural constituents. . . .
Read more on Book of Doctrines and Opinions: https://kavvanah.wordpress.com/2015/08/05/interview-with-adam-ferziger-beyond-sectarianism