Kol Nidrei applies to rash promises made to God, but many antisemites would not accept this and argued that the passage shows that one cannot trust the word of a Jew.
Unfortunately there were Jewish apostates who either suggested or supported this misconstruction, and even some Jewish reformers urged the abolition of the passage, partly because it is rabbinic and not Biblical in origin.
A Reform rabbinical conference in Brunswick in 1844 directed reform rabbis to delete it. However, it had become so entrenched that they retained the melody and some of the familiar phrases.
In Russia in 1857 the czar issued an edict requiring a declaration in the Yom Kippur prayer book that Kol Nidrei applied only to vows which the individual assumed for himself without involving any other person.
The need for Kol Nidrei is spiritual and psychological as well as halachic; it says, “God, under the stress of emotion we may promise You more than we can fulfil. We will do our best, but please understand, and forgive us in advance”.