Those two differences are a pretty harsh judgement on the wisdom of the crowd (or they should tell you you aren't using an especially culturally diverse crowd).
More sympathetically, Album vs Band seems like a confounding factor... the Beach Boys released some astonishing albums, but their overall standing as a band has to also consider the drivel they released. OTOH, Linkin Park are enormously popular as a band, but (in my memory as an alt-rock obsessed teenager in the 00's) none of their albums really broke the surface (relative to the ludicrous levels of play their singles got).
More sympathetically, Album vs Band seems like a confounding factor... the Beach Boys released some astonishing albums, but their overall standing as a band has to also consider the drivel they released. OTOH, Linkin Park are enormously popular as a band, but (in my memory as an alt-rock obsessed teenager in the 00's) none of their albums really broke the surface (relative to the ludicrous levels of play their singles got).