Hmm, interesting—from my perspective, i have similarly strong intuition for love of decades, but mapped differently. For instance i know virtually nobody into 80s music, but 90s r&b and hip-hop are reliable favorites.

My point being: give me a good band, and i can list three at the same time that people don't bring up anymore because they suck. I firmly believe this is nostalgic bias at work, although i dislike taylor swift and justin beiber as much as the next person. Or likely much more. I don't believe it means anything about the decade, just what labels decided people want to hear.

Or to put it another way, my beloved music from the past wasn't even "mainstream popular" then.