On January 16, 1880, the New York Times reported the views of "a prominent electrician," who was unnamed. He said:
... after a few more flashes in the pan, we shall hear but a very little more of Edison or his electric lamp. Every claim he makes has been tested and proved impracticable.
The interesting thing about this article is how reasonable and convincing it sounds, even today. A person knowing nothing of Thomas Edison would probably take it as a conclusive debunking.
For more amusing failed predictions, including one by Edison himself ("The phonograph has no commercial value at all."), see this Wikipedia page.