yankel, you are asking a fair question. In fact, a close friend of mine used exactly such statistics explaining to me why he moved from a RZ to a chareidi community. I readily acknowledge success of charedim in keeping people observant. In fact, my kids went thru charedi schools.
What I am worried about that the defensive mechanism became the only factor to the degree that the community undermines major Torah values. R Soloveitchik perceived this contradiction early on in the 1940s on philosophical level: if we claim that we know Hashem’s truth and are now allowed to participate in the world affairs – how can we hide in the caves? But, beyond philosophy, you can see that in order to maintain the defense, all kind of arguments and behaviors fly in order to convince the followers not to look outside of the fence. All the books on middos and mussar get out of the window. What is the point of getting a majority in the medinah, if the resulting voters will no be Torah-true Jews.