@Perv Otaku
My guess is the music industry just doesn't bother going after lyrics sites, especially because they are just reference pages. Usually copyright enforcement comes into play when somebody else is making money off the thing you made. These stories we publish here aren't profiting us any, but the category of stories and novels in general is traditionally a for-profit enterprise, so it would be something that copyright holders would object to, theoretically.
Likewise, most authors won't object to isolated quotes because it highlights their own out-of-print books (boosting sales), rather than taking away their current sales).