Women never served as ritual slaughterers, for example, although an actual prohibition was rejected in the Medieval legal literature. Nonetheless, when the question arose of whether a woman could, in actual practice, be a slaughterer of animals, the answer given by authoritative Ashkenazic scholars was no. Analogously, even if it is conceptually possible for women to serve as rabbis, communal custom—no small matter in the Jewish tradition—rejects the possibility, just as it rejects women prayer leaders and Torah readers.
Finally, the slippery-slope argument must be given its due. Over the past two centuries, radical changes in communal structure and religious practice have proved, in every case, impossible to control. The evidence seems clear that when radical innovations to ritual originate within tight legal limitations, they quickly exceed those bounds.
The Orthodox response to these changes has been to maintain, the consistency of ritual conservatism. Orthodoxy—including its Modern segment—has refused to legitimate non-Orthodox changes to Jewish practice by giving even the appearance of adopting liberal positions.
Certainly, egalitarianism is a value to be considered, but so is communal unity. There can be no question that the ordination of women would divide the Orthodox community. Whatever their reasons, the majority of Orthodox Jews would essentially excommunicate congregations and organizations led by women rabbis or allowing women to preside at Jewish rituals. Local rabbinical councils would split in half; schools would have to choose sides when making hiring decisions; family members would refuse to attend weddings over which a female rabbi presides.
Charlie Hall writes: There are in fact a lot of recent innovations yet we deny they are innovations. I’ve posted many times here that nobody objected to university education prior to the 19th century. Religious Zionism, at least in its messianistic versions, is another innovation. I’ve seen no evidence of formal Jewish education for women for many, many centuries prior to the early 19th century (and that education began in co-ed environments). Rabbis used to give sermons on Shabat exactly twice each year. And of course our siddur is full of post-Chazal innovations. Nobody prays today from the siddur of Rabbi Saadiah Gaon.
Moshe writes: R. Gil, surely you know that the Gemara explicitly obligates women in daily prayer, and all Poskim throughout Jewish history have affirmed this ruling, with the vast majority of Poskim obligating women to pray the Shacharit and Mincha Amida the same as men.
The only difference is in regards to communal prayer, from which women are exempt and do not qualify for the minyan, and that is the actual reason they are disqualified from serving as chazan.