Bapu, totally agree with your points on this one!
Moshkiae, we will have to "agree to disagree". It is first and foremost about the aural experience, not the visuals. That is still the case in true "concert" music today, which is a different world from Pop/music videos/film scoring (admittedly, a world in decline).
What the film depicted very well, and what sets Mozart, and Beethoven, among a very handful of others apart from the majority of us (including me, of course), is that he (as could Beethoven) was able to write down perfectly on paper what he heard in his head - no intermediary musical instrument needed. In the movie, he was struggling to explain it to Salieri at the end, simply because his mind was outracing Salieri's.
It is also suggested that Beethoven's writing actually got better after he went deaf, as he was less constrained by an instrument - piano in this case. If he had lived longer, based on the harmony/chord structure of his last string quartets, it is possible that most of the Romantic period would not have happened, as he would have quite possibly bypassed it all, with where he was heading in terms of music theory.
Moshkiae, seriously, one of the things that has largely been lost is the ability to simply listen to music - if there is no visual, it doesn't much count. The culture back then, and even into the 20th century had a much stronger auditory component than it does now. With the rise of postmodernism - particularly in its popular form, truth is first and foremost now seen as being visual, so in a way, your comments certainly fall within the norm.
Granted, performances back then were strictly always "live" so there certainly was a visual factor - moreso with Opera, of course.