Why would ppl from other countries know the internal division of the US. Thats like asking ppl to know brazillian regions. Or russian ones, or Chinese ones. Those are equally big countries but ppl are not expected to know those internal borders and names.

People make fun of Americans not only because they were ignorant of global geography, but also because they didnt generally show much interest in it. It is a response to american exceptiolism i think. Making fun of those that think that the USA is the best country and all that really matters.

Still i dont find making fun of Americans for that very funny. Specially because its not that true anymore.