For rock music to have any relevance or vitality in modern culture, it would have been hard to rely on bands like Guns 'N' Roses, Bon Jovi, Def Leppard or Poison; not discounting their talent or musical ability of course. These bands were mostly stagnant, rehashing themes and motifs that had been used, reused and recycled countless times by the 80's. If it were up to them, rock music would have gone the way of the dodo, or at least confined only to people who like Guns 'N' Roses and 70's classic rock and nothing else.
Now bands like Sonic Youth, Pavement, My Bloody Valentine, Jesus And Mary Chain, R.E.M, Husker Du, The Pixies, et al; were; on the other hand; giving rock a jumpstart in creativity, originality and dynamism. They pushed the envelope of what rock music could be and what could be accepted as rock. But they did all their experimentation and envelope-pushing within the boundaries of rock music. This is key to understanding the impact they had. They pushed rock forward into the 21st century, hurrying it along and keeping it fresh, alive and urgent.
Though never as popular or mainstream as the bands mentioned in the first paragraph, they nevertheless had impacted and contributed to the evolution of rock music in a large way; and any similar impact they would have on popular culture or the mainstream would be through the way of rock music of course. Unfortunately in its current incarnation, popular rock music is nothing more than a showboat of fashion, trends and posturing. Popular culture as we know it in the 21st century is, after all; and actually has always been; nothing more than a marketing and image hard sell, the business of ideals and cardboard idols.
The music has always been secondary. Therefore bands like Bon Jovi and Poison and people like Britney Spears and Fred Durst excel at the business strategy and marketing values that dominate the music industry, while bands like Sonic Youth, The Flaming Lips and people like Thom Yorke and Devendra Banhart continue to focus on making music that is exciting, fresh and relevant. But as long as rock music is still relevant within popular culture and the mainstream(which, judging by the standard of Fall Out Boy, Good Charlotte et al, it isn't
) Sonic Youth and other like-minded bands will remain relevant and vital within culture.
P.S. I wasn't aware Billboard had a Top Independent Albums chart. I'm not sure if this is a good thing.
http://en.wikipedia.org/wiki/Billboard_charts