I suppose the problem popularity presents is its conflation with value. The heights that single works of art can reach these days are staggering. A CD of lame, trite trash can sell millions worldwide these days--that's the common example. Yet little if anything at all truly deserves to produce so much income, or have so much spent on its mass production and marketing. It's merely a massive population, technological marvel, and simple barriers of scope and choice that place a limited selection of texts (songs included), both remarkable and unremarkable, in the popular domain.
Take heart, chthonic, the problem will be mostly solved when all information eventually becomes free and widely available.