In relation to the Passover text, the response to some deviations was even harsher. “One who conducts himself in accordance with this custom (of some changes to the text), there is no need to say that he has not fulfilled his obligation, rather anyone who does this is a heretic, he is a ‘divisive heart’ and denies the words of the sages OBM, disparages the words of the Mishna and the Talmud, and all communities must excommunicate him and separate him from the congregation of Israel…until they return to the good and accept upon themselves to follow the custom of the two Yeshivot”. Regardless of the merits of such conservatism, this is the understanding of tradition within which I practice my faith.
Regardless of the rule that the genie cannot be put back in the bottle, perhaps in this case this is possible. While rejection of the basic premise of the Seder has not been given a lot of tolerance in the tradition, at many Seders today very challenging questions are welcomes with open arms. At least they bothered to show up! The concern for the suffering of our enemies at the Seder is well documented with the idea of pouring out a little bit of wine for each of the plagues in recognition of the suffering of the Egyptians.