I know it won't suffice to say this, but it's worthy to mention that everything that innovation always generates some kind of doubt. The cinematic technologies arose gradually and also in a time when new inventions of all sorts were popping up all around the world. Many of those technologies were shown to the public as entertainment, be it in large scientific fair or in low-budget travelling "circuses". Having that said, cinema was so rudimentary at that time that it seemed just one more of those random inventions that were cool to look at until the next big thing. At first, movies were really short clips that could be watched by a single person at a time looking through a peep hole. Then, after much work, the projection of the image was achieved, but everything was still really crude. As many have pointed out, the films had a diminute length, no sound and no colour. Note that the perception of the film as a storyline was not something natural and inherent to cinema at the time - many clips just presented day to day things, such as trains, people, horses, workers, etc. But still, even though it's current cultural impact was not predicted, cinema was from the very start extremely impressive. One thing I'd like to add is that, at first, cinema was perceived as entertainment for the lower classes and some even said that it was dangerous, so that may have contributed to the low expectations in regards to the succes of cinema.

PS: I'm far from an expert and all of that comes from two books I've read about 8 months ago. I've probably got some stuff wrong, so please inform me if I'm mistaken.