Its all about selling image.
The Libertines had/have an image the record company can sell. Their slacker/can't be @rsed image appeals to a certain demographic and is seen as a kick against the tightly controlled music industry. If that particular image appeals then chances are you will buy the music.
But then we all know that don't we?
A couple of years back I was working on a project involving Folk music, not the finger in the ear stuff, but contemporary folk music, and these musicians were simply astonishing in their ability.
They would just turn up and play, no Autotune or studio jiggery-pokery, all in tune and in time, complex harmonies and arrangements.
But they are pretty much unknown outside their locality and most of them have other full-time occupations and play for the love of the music.
Intelligent, entertaining, talented people but if they walked past you in the street you wouldn't notice them.