nellypope - I think you are confusing the two strands of Amy Winehouse's appeal to two very different media markets.
On the one hand, she has a massive following for her wonderful writing and singing, which is not based at all on her personal live.
On the other, she has an appeal to tabloid readers who would not know a decent singer if one jumped up and bit them. These are people who love to hold up their hands in horror at the dreadful lifestyles of modern musicians - they have been tutting and puffing since the days of The Stones, and it's a huge market in newspapers and magazines.
The important fact is that the two are mutually exclsuive - few if any people buy Amy Winehouses's music because of her drug habit, few Middle Englnaders who love to look down on the less fortunate would buy the music of someone who'se continual spiral into addicition they love to be titlated over.
Happily, the two lots of people occupy different worlds.
The nusic industry is a harsh ficle world, I know, I work in it, but it's not as simple as you are trying to make it sound.