It's only "racism" in the provincial US preoccupation that "everything said that touches on a population/ethnicity/race is racism". Not in the "X are inferior/KKK/etc" sense, which is what we should be concerned with.
I, for one, don't appreciate taking lessons about how a joke is racist from people from a country that had slavery until the 19th century, segregation since the 1970s, and widespread systemic/popular/law enforcement racism problems today. As if their experience is the universal standard that should be applied to the global population here on the internet. That's, if not racist, surely imposing upon others...