For almost every form of -ism and -phobia that our liberal betters wish to demonize, there is a reason. And usually more than two.
Racism, sexism, homophobia, xenophobia, classism, transphobia, Islamophobia, antiSemitism, looksism, ageism, ableism, even antiziganism!...there are reasons, and good reasons, for all of them.
They are not --as our liberal betters demand that we makebelieve-- simply groundless, baseless, evil attitudes arising from nothing more than groundless, baseless evil minds, without evidence or foundation, massive denials of the blindingly obvious truth of universal equality, (an equality which, for some strange reason, has escape the noticed of the entire human race until ten minutes ago.)
Universal equality. Talk about groundless, baseless, evil attitudes without evidence or foundation! (Young Mr Kurtagic ramps up the critique made by the elder Dr Kekes that egalitarianism is a huge mistake and leads to terrible evil.) "Our common humanity", in the sentimental sense in which it is usually meant, is the least informative and consequential thing about us. It's as meaningful as saying, "All cats are cats!"
And while I'm at it, stereotypes are only offensive because they cut so close to the bone, not because they are insultingly mistaken but precisely because they carry so much truth in them. Each offended group's comedians relies on the truth of the stereotypes to make them laugh. They all see it.
One of the fundamental and unchanging realities of the human species is that we live in groups, groups of all kinds, and that many of these groups --including the most important ones like families and tribes-- are in constant competition and conflict with one another. Competition and conflict are structured into the very nature of the species because of the very nature of the planet on which we have come into being, where death is universal and ever at-hand, and life is marked by scarcity, contingency and flaw. Competition and conflict are not moral flaws in our species character, they are the conditions of our survival, about which we are not given a choice. You may as well condemn humans because we eat organic matter.
Survival is both an individual and a group concern, but a group concern above all, since it is your group(s) that allow you to survive as an individual. So in an important way, it does not matter whether an ism, a phobia or a stereotype is "true". That is a determination that will always be clouded by self-interest and will never convince the Other who is in competition and conflict with you. What matters is to find your group(s) and fight for your survival. Because that's what all the Others are doing.
Everyone who is not a Foolish White Person knows this and lives by it.