You don't have to be Dutch. Everyone jokes about Belgian
In France, they're the butt of a lot of jokes involving intellectual simplicity. Same with blond jokes. And from what I gathered, the Belgian tell the exact same jokes about the French (plus the evident arrogance that's a common shared trait among my people
).
The jokes Notty's talking about are not the same kind, though. I, for one, find them hilarious in their dark humorous tone. Very British, one would say. It's not like she wrote: "Oh, this guy is xxx, so he's a bastard like all of his kind".
Never forget the "joke" part. People nowadays only seem to focus on their wittle feelings getting hurt.