Answer:
He means that the white men broke their tradition and customs. They lost their land and their religion. When the colonialist dominate their people.
Explanation:
Since the arrival of the colonialists, upset be the fact that the white men have come and completey disregarded the Igbo sense of justice. Obierika points out the impossibility of the colonialists understanding anything about the Umuofians without speaking their language. He points out the ludicrouness of denigrating unfamiliar customs. He does not blame only the white man, he also feels that the Umoufians who have converted to Christianity have consciously an wrongly turned their backs own their own brothers.