I understand that another study showed people turn away from pop music at an average age of 37. Quite understandable: IMHO there hasn't been a decent band since Queen.

Perhaps more relevant is Sturgeon's Revelation, that in any field of human creative endeavour, 90% of the result is rubbish. My own extension to this states that a further 9% is mediocre, leaving just 1% that is genuinely good. The rubbish is soon forgotten, the mediocre survives long enough to become unfashionable, the good has staying power. Modern music (or art or literature) inevitably seems worse simply because its rubbish is still with us.