I think that if somebody is bad or good from day one, there's no real
interest in what happens to them on one level. But take someone who you kinda
liked, and thought was fun....and slowly they begin to slide into something
dark and terrible...you *feel* for them, you worry about them, you're watching
it like a car accident in slow motion. And then there's the one you thought
was rotten to the core...and now that character seems to be moving toward
something noble, but tragic...again, you get caught up in it.
Life, and good storytelling, is about *change*. Or as Mr. Dylan said,
"Any man not busy being born is busy dying."