Big difference? Do you seriously think that the entire field of artificial intelligence research produced nothing usable until today? For as long as there were AI algorithms there were also attempts to commercialize them (with varying success). The problem wasn't that all of those algorithms turned out to be useless, but rather the mismatch between hype and reality.

You should look into the history of expert systems for a classic example. With things being as they are, deep neural networks might very well go though the same cycle, which is not a good thing for the AI field in the long run.

Caution and skepticism are not the enemies of research and engineering. Hype is.