Americans are more asian friendly,

and yeah, it should be a case-by-case case basis but a stereotype HAVE to come from somewhere right ?

Stereotypes say all hispanic people are the same. Yet:

Spaniards and mexicans don't look alike at all. They share completely different traditions. They even speak a different variant of spanish from each other. They are actually separated by us by an ocean. We don't even share the same face shapes or even skin tone.

Yeah, some stereotypes are totally made up.