Generally, the people who entertain these stereotypes are those who aren't affected negatively by any stereotypes. It's part of what is sometimes referred to in sociology as the folk theory of racism, which is built on three tenets:

1) race is a significant biological fact, whereas most sociologists agree that it is entirely a political fact

2) racism only exists where people specifically intend to be racist, i.e. that it is entirely a manifestation of individual belief, and

3) that racism is a natural and unavoidable result of the human condition.

You can see the manifestations of this theory on this thread, especially points 2 and 3. Consider the responses here to the effect that because there was a greater point about certificate authorities being made (and thus no specific racist intent exists) no racism is present.

And also consider the responses to the effect that stereotypes are a necessary part of humor, without which apparently no effective communication would be possible. It's practically a claim to the right to stereotype other races. In another response, a commenter points out that there also exist stereotypes of English and French people, as though all stereotypes are morally equivalent.