And nobody really thinks that.
My god, what a time to be alive, when you can't make simple jokes anymore, because somebody somewhere always is offended and thinks there must be some racist agenda in place.
Even as a German with a total lack of humour (and an Italian motorcycle with strange quirks in the garage) I found this funny. Funnier than the Holocaust at least.
As an Italian expat, I can assure you this is unfortunately incorrect.
> you can't make simple jokes anymore
No, you can't make jokes based on lazy stereotypes that end up affecting the lives of millions. It's a different thing. It might have been fundamentally innocuous, back when populations didn't mix as much as we do today, but now it's a real problem. If I go to a job interview and the potential employer assumes Italian == lazy, I'm done for. That's the casual bigotry that these jokes end up entrenching.
Italy has a pretty big space-related industrial sector, and excellent academic standards in some fields. It might not produce geniuses with the same frequency of the past (Galvani, Volta, Marconi, Fermi and so on) but it's not some random backwater.