Superespecialization is a (post)modern disease

Every scientist knows a colleague who is expert in some subject. Probably this person is an erudite in this subject, and is able to discuss this matter with the other experts in that matter in all world. This person is, however, unable to discuss any other subject. The Germans have a term for this: Fachidiot (translated as something like "idiot specialists").
The colleagues in Pedagogy usually blame (at least here in Brazil) the Napoleonic university reform for this state of affairs and state that it is post-modernism that is changing this.
I always doubted this. If we go back to the XIX century and see the biography of people like Euler, Rankine, Faraday, Darwin, we see that they were far from being specialists in just one subject. They were all polymaths.
I read recently an article about Heisenberg and discovered, not as far as the early XXth century, that he had a hard time getting his title (Dr rer nat) because he had problems with experimental physics. So he was expected to understand things other than the subject of his thesis to obtain the title.
I guess the superespecialization is a recent phenomenon. If you are a university professor like me and does not wish ending up as a "Fachidiot" here is my advice: try teaching something outside your area of expertise. You will find out it is funny to learn something new and that, with your intelligence, you will discover connections with yout own research field, perhaps even something innovative.