Growing up in apartheid South Africa, daughter of a Holocaust Survivor and a Boere meisie, I never heard one word about Germans being bad or the British being bad (Boere war) or blacks being inferior, or anything else that was derogatory to anyone else.
When my British headmistress (at a private elitist school) wrote to my late father to complain about my objecting to certain things, my father wrote me a letter to in which he explained that he had told my headmistress that he would not stop my freedom to object and that I needed to be an independent thinker.
And that is what I have become.
The fault of my cultures and tribes is that they cannot stand apart from their culture and tribe. So they pass on long felt prejudices and historical inaccuracies to their children, and yes, every adult on this planet is responsible for the views they hold.
It has cost me dearly in this life when I have told bosses that their actions were morally wrong. I would watch my work mates go along with their bosses while I paid the price. I am left in eternal poverty.
So, yes, to a greater or lesser degree, we are all individually responsible for not speaking up for fear of our individual safety and loss of income.