The human brain is so arranged that it constantly generalizes incoming information. Thanks to this ability we can learn quickly: we just show a couple of photos of the gepard, and we will know exactly how the gepard looks.

This same ability helped our species to survive, because generalization helped to identify and avoid danger. Dangerous animals, situations and so on. Everything has certain signs that our brain is trying to identify.

No one doubts that such signs as "sports suit", "seed slide", "sitting on the courts" can hide a danger. And we know that the hoops are worth bypassing.

But also, our brain doesn’t care what signs to identify. It can be both beard, ethnicity, and hair color, etc.

So, if the Chechens are not treated very well, it means that a sufficient number of their representatives behaved inappropriately, so the brains of other societies simply made a generalization.

It is just nature.