Ojgalli,
There is a lot of science behind the claims made on the links you quoted. The problem is that science is not always trusted and fear of missing out on a potential performance improvement continues to drive people to try things.
Another thing not mentioned in these links is that some audio gear is very much more susceptible to cables than others. For example, the principle of a high input impedance and a low output impedance is desirable for audio components...this minimizes the effect of a coupling cable (often to a point of being audibly negligible when sufficiently high contrasts are employed)
However, not all audio components are designed according to these principles.
There is a lot of science behind the claims made on the links you quoted. The problem is that science is not always trusted and fear of missing out on a potential performance improvement continues to drive people to try things.
Another thing not mentioned in these links is that some audio gear is very much more susceptible to cables than others. For example, the principle of a high input impedance and a low output impedance is desirable for audio components...this minimizes the effect of a coupling cable (often to a point of being audibly negligible when sufficiently high contrasts are employed)
However, not all audio components are designed according to these principles.