Famous physiology professor Pierre Pachet in 1872 commented on Louis Pasteur's theory that “Louis Pasteur's theory of germs is ridiculous fiction.” But now his theory has gained worldwide acceptance and is base point for many other theories and discoveries in microbiology.
In 1876, after the exhibition show of telephone arranged for the American president Rutherford Hayes, he commented that “This is an amazing discovery, but who would want to use it?” Within two years telephone gained popularity in America.
“It doesn't matter what he does, he will never amount to anything”. This was what Albert Einstein's teacher told his father about him in 1895.
Charles Duell, Commissioner of the U.S. Office of patents, in 1899 has said that “Nothing new would be invented now; whatever could be invented has already been invented”.
A Professor of Strategy, Marechal Ferdinand, in 1911 has said that “airplanes are interesting toys but of no military value”.
The idea of actors and actresses speaking in movies wasn't welcome by Warner Bros. H.M Warner in 1927 commented that “Who would want to hear the actors talk?”
In 1939, The New York times wrote that "Americans are too busy to spend any time with TV. They can never be popular in America."
Thomas Watson, Board Chairman of the IBM computer in 1943 said that “I think there is a world market of maybe five computers” and in 1977, Ken Olsen, founder of Digital Equipment Corp. commented that “Who would want a computer at home?”
Bill Gates in 1981 has thought there would never be a requirement of a system which has more than 640KB of memory.
We cannot blame any of them. All of them have put extensive efforts in their respective fields. It is just the conditions of their time that made them speak like that.