Circumcision, for (orthodox) Jews, is one of the most fundamental conditions for identification and belonging to that group. Leaving a Jewish male baby uncircumcised would most likely lead to feelings of alienation and isolation later on in life – feelings which could have significant psychological impact and could largely negate the benefits one gains from strong communal structures.
Regardless of the process's inherent morality, a blanket ban may cause more harm than good. Cultures have dependency trees, like a Jenga tower: remove one block, even one that, in isolation, is a negative, and you risk destabilizing the entire structure and causing significantly more net harm than that single negative you erased.
More generally, I'd propose a corollary to Chesterson's fence [1]: Before you (in righteous external-observer outrage) destroy an element of a culture, make sure you understand what role that element plays, and what harm you may cause with such heavy handed destruction.
[1] https://en.wikipedia.org/wiki/G._K._Chesterton#Chesterton.27...