Underground music is cool until it's popularized by the sort of people that wear purple American Apparel hoodies and those neon shades that Kanye West wore that time.
These bands usually make a couple of chart bothering singles then the same kids that brought them into power decide that they don't like 'their flavor' anymore and move onto the next cool band to ruin.
While all this is happening bands that were created with the soul purpose of making it big (not mentioning any names here), they stay on top to a certain degree for most of their professional career, sometimes shadowed by the newest obscure R&B or commercial house track that Kiss FM decide is what people should be listening to that week/day/hour, until eventually the bass player dies in a horrific rock climbing/sky diving/extreme yachting accident and the band decide that he was so much of a creative force that they can't go on anymore and disband.
After this they're left with noting other than their millions and millions of useless pounds they've amounted and are left in the rain clutching a handful of soggy broken marriage vows after that super model wife decides that she preferred that guy who won Big Brother after all. At the end of the day, he's more sensitive and wears crocks.
The big bands will keep a few die hard fans that will hug their favorite album to the grave and everyone else will move on loving whatever replaces them.
The same doesn't occur for your underground scene, since when an underground band gets kicked from the charts they manage to keep face, if not for their niche fan base then for their mums who can't bare to see their beloved sons and daughters go to waste after all those guitar lessons that were payed for, largely on granddads inheritance. So instead they slip back into their skinny jeans and sleeveless Blondie t-shirts and tour the country with their radical new album, complete with what they laughingly call 'a new sound'. Because of this many of their hardcore fans absolutely hate the new album since it's all new and scary, most of them are still recovering from the shell shock of their hero's falling from grace, this all just becomes too much. Many of these hardcore fans will often move on to start their own bands to prove that there are kids who can still 'keep it real' without the help of the media but sooner or later follow exactly the same path as their down trodden predecessors.
And thus the cycle continues.
