Just like I claim "everyone lies", I claim everyone has prejudices. We all decide what we want near us, what's different from us, what we want in our immediate surroundings, or sphere, what we want affecting our children. Just as people who claim they don't lie are being disingenuous, people who claim little to no prejudice are being disingenuous. Not to justify ethnic or religious discrimination, but at least when people are forthright about it, you know where you stand with them. That "honesty" is more respect given than from people who claim to be your friends, for some principle or self serving purpose, but secretly loathe you, are jealous of you, or make every excuse to not be around you.
People "love the self" in different manners. Healthily loving the self, by nature, practically necessitates, begs, protection of the self and avoidance/removal of what one considers dangerous or otherwise aberrant. Only if one "has a lack" of this, do they manifest some altruistic "love for all", and this is the very foundation of narcissism, and thereby deceit, because one truly can only love others as one loves the self, because narcissism, while it appears "too much love for self" is overcompensation for a deep, specific "loathing of self". So you have a spectrum, a continuum, of left side loving self genuinely and expelling what's foreign or right side loathing self and accepting the foreign to change or otherwise adversely affect the self. All people fall somewhere in this, generally in shades of gray, but neither is necessarily more "correct".
I, for example, have a prejudice against feminists. I feel as a colored person looking to a white supremacist toward them. Many feminists claim they don't "dislike" men, many white separatists claim they don't "dislike" people of other ethnicity. In truth, females have always been powerful, always been just as integral, always been just as influential as males, or we couldn't have gotten here. They look to supposed "power" men have and they lust for similar "power" or "control", disregarding those "powerful and controlling" men maltreat not only women but other men as well, and for some reason want to be "that". So it stems from a feeling of lack of power, lack of control, and manifests as irrational disdain, and in extreme cases leads to hatred, just as racial bigotry.
So some argue "bigotry of bigotry isn't bigotry", but it is. It's entirely too difficult to separate the "actions" or "ideals" from the "person", and you just end up expelling the person from your immediate sphere. It works out the same way, it follows to exactly the same end. So there is no person with zero bias, unless the bias is expressly with the self, and that inevitable leads to projection of the self so on high, one holds himself above existential premise, real or metaphysical. That is the true origin of what we consider evil. That is a more destructive force than any outwardly bigoted group of people could ever dream to perpetrate.