Alexander Bell-
"One day in the Future, I hope there will be 1 phone in every City of America!"
Some other critics also said that CD's and Mobile Phones woudn't catch on. CD's I reckon because Tapes had just burst onto the scene. Oh yeah, and the prices of things back then:
£40 for a Biro back in 1915
£70 for a Calculator in 1960
Any others?