The author criticizes the score for Chariots of Fire because a synthesizer score does not fit a film set in the 1920's. This is inconsistent which his criticism of the score for The Third Man, which did fit its time and place.
The article was just one guy's boring opinion.
There, corrected it for your dyslexia.
One of the bonus features is a short featuring Mr Karas playing his instrument in a Viennese night club. It's fascinating to see the closeups of his hands. He later opened a club of his own, based on the popularity of his music.