Not necessarily. As was discussed earlier, it may not be the reproduced music as such, which the user finds engaging; it could be many other factors, like valves that glow blue. People acknowledge the placebo effect when talking about it in isolation, and are even prepared to accept that of course their impression of an audio system is swayed by many things other than the reproduction of music. But in the next post have forgotten all about it when relating how their latest tweak "sounds".
Surely. We know it is all placebo - it is why audiophiles queue to buy amplifiers using blue LEDs to create the blue glowing.
Bias exists in every sighted report. We should know how to read between the lines and analyze these subjective reports using our own experience and knowledgeif you want to extract something useful for us. It is why it is important to list the recordings, write details and readers should know the poster system, preferences and previous history.