I'm not sure this is the exclusive domain of audiophiles. Look at golf, fishing, hunting, etc. It seems every hobby is bombarded with products of dubious practical value, even though the "improvement" may be measurable under some staged circumstances. (How many golfers buy the latest club/ball that so-and-so pro uses it... in spite of the fact it was designed for the pro's swing speed which is twice that of the consumer?)
Besides, if it wasn't for the BS, what would we do?