Why do people ask questions that generalise about a whole group?

Pure ignorance

It is all about the language that is sitting in our brains or say memory. For example, I could say you should have added "Why do (some) people ask...?" rather than why do people.

Firstly, we do not want to exactly figure out such and such a person is a racist or sexist and son on.

Secondly, as I told you our memory has habituated to unconscious language recordings, which is too difficult to change with out a very conscious practice.

Thirdly, that is how we normally think. Here we is again a very general pronoun. Because in that we you alone may be an exception. Still it is how we normally think.

Fourthly, purposeful. Which is what I guess you mean by your question. If it is purposeful, you question has no answer and no meaning in asking. Such people can be taught only through a contrary experience, that they come across a situation where they were forced by that very situation to accept a help from another race or people.

Yes I agree. I'm an Aussie and can't understand people who are racist. There is good and bad in ALL races, countries and from all walks of life. You should treat people the same as you would like to be treated i.e. with respect and dignity. We are all the same under the skin.

obviously, they are not that smart and yes that is a form of prejudice. I don't believe in racism necessarily, because it is not a proven scientific phenomenon.

I think ppl just rush and type out their questions. I really don't think they mean to generalize.

It's easier to assume than to think.